Occludator, face bow, occlusion-confirming system and temporomandibular joint-reproducing system

ABSTRACT

It is intended to provide an occludator whereby joint movements at occlusion being similar to the actual tempromandibular joint movements of an individual patient or ideal movements can be reproduced, and a face bow to be used for the occludator. To achieve this object, an occlusion plane against a standard plane is accurately drawn by using the above face bow F whereby the occlusion plane can be drawn at a high accuracy. A solid model of the tempromandibular joint similar to the tempromandibular joint form of an actual patient is used as the joint unit of the occludator K, while the positional relationship in the body at occlusion is three-dimensionally reproduced in the occludator I with the use of the above-described face bow F. It is also intended to provide an occlusion-confirming system and a tempromandibular joint-reproducing system with the use of an occludator whereby joint movements at occlusion being similar to the actual tempromandibular joint movements of an individual patient or ideal movements can be reproduced. To achieve this object, the tempromandibular joint of the body is photographed with a local X-ray CT device to give three-dimensional image data and then a solid model of the tempromandibular joint is constructed based on the three-dimensional image data. This solid model is employed as the joint unit of the occludator K and the positional relationship in the body at occlusion is three-dimensionally reproduced.

TECHNICAL FIELD

The present invention relates to a dental occludator for confirmingocclusion, a face bow for the occludator, an occlusion confirming systemwhich can be used for the fabrication of a prosthesis for teeth andtreatment of a temporomandibular joint, etc., and a temporomandibularjoint reproducing system usable for the occlusion confirming system.

BACKGROUND ART

As described in JP2000-262545A (see FIG. 1), a conventional occludatorcomprises, e.g., a lower bow-shaped part where a lower jaw tooth mold ismounted, an upper bow-shaped part where an upper jaw tooth mold ismounted, and a joint for connecting the lower bow-shaped part and theupper bow-shaped part, so that an artificial joint movement such asopening/closing of the tooth molds is obtained and a state of occlusionis reproduced. The occludator is used in the treatment of the occlusionof upper and lower teeth and the fabrication of prostheses.

The joint described in the conventional document is configured such thata maxillary rotation axis (2), which is combined with the upperbow-shaped part and is circular in cross section, is placed from aboveat a sagittal condyle path tilt angle on a concave combined with thelower bow-shaped part. A plate spring (3) applies an urging force toprevent detachment. A target joint movement is intended to be reproducedby specifying the sagittal condyle path tilt angle.

JP11-28217A (see FIG. 4) describes another form of a conventionaloccludator. The joint of the occludator is constituted of a condyle (12)composed of a sphere which is mounted on a lower bow-shaped part andprotrudes upward, and a condyle box (17) mounted on an upper bow-shapedpart. An articular fossa (condyle path) is represented by a plane of thecondyle box.

According to the occludator of the latter conventional example, aBenette lift mechanism (15) for lifting an upper jaw tooth mold, fromthe condyle, separately from the condyle box is provided on the lowerbow-shaped part (base). Thus, with respect to the position of the lowerjaw tooth mold which is faithfully and accurately mounted as in a stateof a living body, reset can be arbitrarily made on the occludator to alower jaw position diagnosed as the most suitable for a living body, sothat a target joint movement is obtained.

In the conventional occludator, the theory of overcompensationreproduction is used. The configuration of the joint is devised and thejoint is adjusted on the basis of the overcompensation theory. In thetheory of overcompensation reproduction, by setting a condyle pathregulating mechanism of the occludator to make movements slightly morethan the temporomandibular joint movements of an actual living body,prostheses fabricated on the occludator readily make diastases duringlateral movements in an oral cavity. With this theory, even on anoccludator less capable of adjustment, moderate prostheses can befabricated with just a few adverse actions.

However, some errors inevitably occur in mandibular movements reproducedby a semi-adjustable occludator which is less capable of adjustment. Aprosthesis fabricated by such an occludator may cause an error which iscollision with or separation from opposed teeth during lateralmovements. Particularly when providing balanced occlusion for a fulldenture, a prosthesis may fail due to any of these errors.

Diastasis (right and left artificial teeth of a full denture occlude ona working side and separate on a balanced side) does not cause anyproblems when prostheses are fabricated for a few teeth. However, when anumber of teeth are lost or in the case of a full denture, a stretch ofthe theory suggests that flat surfaces are better for the occlusionplanes of artificial teeth, which may lead to misinterpretation. Flatocclusion planes have low mastication efficiency and cause an enormousload on alveoli and periodontia. Thus, flat surfaces are not alwayspreferable. Rather than flat surfaces, the cusps of molars should besharpened as much as possible.

In this sense, various kinds of average value occludators (an averagevalue is used as a condyle path angle), semi-adjustable occludators, andtotally adjustable occludators (although a condyle path angle can bepersonally adjusted, the adjustment is difficult and is not correct in athree-dimensional manner) are conventionally produced and prostheseshave been fabricated by reproducing occlusion by means of theoccludators.

Although various kinds of inventions are devised for joint movements onoccludators as described in the conventional examples, the inventionsare all based on a joint structure composed of a rod or sphere circularin cross section. An angle, a position, etc. are intended to be adjustedin compliant with the overcompensation theory to obtain joint movementsrequired for prostheses but an actual joint shape is not intended to bereproduced. That is, as described above, dental care workersconventionally comply with the theory of overcompensation reproductionand have no idea about reproduction of an actual shape of atemporomandibular joint. This fact is evident from JP11-146889A whichrelates to an invention of an artificial temporomandibular joint. Inthis invention, an articular head is shaped like a rugby ball.

In this invention, a face bow is used to obtain an occlusion planerelative to a predetermined standard plane (e.g., a standard plane suchas the Frankfurt plane and the Camper's plane) of a target patient andreproduce the plane on an occludator.

In the conventional face bow, for example, ear rods provided on the endsof right and left legs are inserted respectively into the externalauditory meatuses of a patient, the body of the face bow is disposed onthe predetermined standard plane, and the occlusion plane position ofthe upper jaw of the patient is obtained by a bite fork mounted on theface bow.

Then, the occlusion of an upper jaw tooth mold and a lower jaw toothmold is positioned on the obtained occlusion plane, and the upper jawtooth mold and the lower jaw tooth mold are mounted and reproduced onthe corresponding occludator.

For example, in the case of an occludator with the Frankfurt plane, whenthe face bow is mounted on the patient, it is better to set the face bowon the Frankfurt plane. However, as described above, a joint of theoccludator is constituted of a sphere and a platy member and thus theface bow does not have to be correctly positioned on the standard plane.According to the mechanism of the conventional face bow, it is difficultto correctly make setting on the standard plane. Thus, the face bow isnot so correctly positioned on the standard plane in ordinary cases.

Moreover, the conventional face bow is made of a material not permittingthe passage of X-ray beams, e.g., a metal.

DISCLOSURE OF THE INVENTION

The prevent invention is devised in view of the above-described pointsand has as its object the provision of an occludator which can reproducea joint movement closer to an actual temporomandibular joint movement ofa patient during occlusion and a face bow used for the occludator.Another object is to provide an occlusion confirming system and atemporomandibular joint reproducing system which can reproduce an idealjoint movement or a joint movement closer to an actual temporomandibularjoint of a patient during occlusion.

In order to attain the objects, an invention according to claim 1 is anoccludator comprising a lower bow-shaped part for mounting a lower jawtooth mold, an upper bow-shaped part for mounting an upper jaw toothmold, and right and left joints which connect the lower bow-shaped partand the upper bow-shaped part and enable a movement including anopening/closing movement and a lateral movement, characterized in thatthe joint comprises an artificial condyle which is detachably mounted onthe lower bow-shaped part and protrudes upward and an artificialarticular fossa which is detachably mounted on the upper bow-shaped partand is opposed to the artificial condyle from above, a contour of atleast one of the artificial condyle and the artificial articular fossais shaped according to a contour of the mandibular condyle or themaxillary fossa of a person whose impression has been obtained duringthe fabrication of the upper jaw tooth model.

According to the present invention, a joint movement close to an actualshape of a temporomandibular joint can be reproduced by the occludator.

Regarding the configuration according to claim 1, an invention accordingto claim 2 is characterized in that the occludator comprises an elasticbody for applying an urging force in a direction of bringing the lowerbow-shaped part and the upper bow-shaped part relatively close to eachother.

According to the present invention, the opposed artificial condyle andartificial articular fossa can be kept in contact with each other and asmooth joint movement can be obtained.

Regarding the configuration according to claim 1 or 2, an inventionaccording to claim 3 is characterized in that the joint is constitutedof an upper joint and a lower joint which are opposed to each other, theupper joint is constituted of an upper mounting member supported by theupper bow-shaped part, a maxillary fossa model, and first mounting meansfor detachably mounting the pedestal of the maxillary fossa model on theupper mounting member, and the lower joint is constituted of a lowermounting member fixed on the lower bow-shaped part, a mandibular condylemodel, and second mounting means for detachably mounting the pedestal ofthe mandibular condyle model on the lower mounting member.

According to the present invention, the maxillary fossa model and themandibular condyle model can be replaceable.

Regarding the configuration according to claim 3, an invention accordingto claim 4 is characterized in that the first mounting means isconstituted of a male screw part formed on the upper mounting member, acylindrical member having a female screw formed in an inner surface, thefemale screw enabling to be screwed to the male screw, and an innerflange which is formed integrally with the cylindrical member, forms ahole permitting the passage of the maxillary fossa model, and can makecontact with the periphery of the pedestal of the maxillary fossa model,and the periphery of the pedestal of the maxillary fossa model issandwiched between the upper mounting member and the inner flange byscrewing the female screw to the male screw.

According to the present invention, the maxillary fossa model can beattached and detached with ease.

Regarding the configuration according to claim 3 or 4, an inventionaccording to claim 5 is characterized in that the second mounting meansis constituted of a male screw part formed on the lower mounting member,a cylindrical member having a female screw formed in an inner surface,the female screw enabling to be screwed to the male screw, and an innerflange which is formed integrally with the cylindrical member, forms ahole permitting the passage of the mandibular condyle model, and canmake contact with the periphery of the pedestal of the mandibularcondyle model, and the periphery of the pedestal of the mandibularcondyle model is sandwiched between the lower mounting member and theinner flange by screwing the female screw to the male screw.

According to the present invention, the mandibular condyle model can beattached and detached with ease.

Regarding the configuration according to claim 3 or 5, an inventionaccording to claim 6 is characterized in that the first mounting meanscomprises a ring-shaped part which is formed on an end of the uppermounting member and has an inner concave part permitting the insertionof the pedestal of the maxillary fossa model, and a fixing screw whichcan laterally penetrate the ring-shaped part while being connected tothe ring-shaped part by screwing, and has an end capable of beingscrewed inward or in contact with the side of the pedestal of themaxillary fossa model.

According to the present invention, the maxillary fossa model can beattached and detached with ease.

Regarding the configuration according to claim 6, an invention accordingto claim 7 is characterized in that the pedestal in cross section andthe concave part of the ring-shaped part are both polygonal, and thepedestal is so shaped as to be engaged with the concave part of thering-shaped part.

According to the present invention, it is possible to readily positionthe maxillary fossa model in the lateral direction (X-Y direction) andthe circumferential direction.

Regarding the configuration according to claim 3 or 4, an inventionaccording to claim 8 is characterized in that the second mounting meanscomprises a ring-shaped part which is formed on an end of the lowermounting member and has an inner concave part permitting the insertionof the pedestal of the mandibular condyle model, and a fixing screwwhich can laterally penetrate the ring-shaped part while being connectedto the ring-shaped part by screwing, and has an end capable of beingscrewed inward or in contact with the side of the pedestal of themandibular condyle model.

According to the present invention, the mandibular condyle model can beattached and detached with ease.

Regarding the configuration according to claim 8, an invention accordingto claim 9 is characterized in that the pedestal in cross section andthe concave part of the ring-shaped part are both polygonal, and thepedestal is so shaped as to be engaged with the concave part of thering-shaped part.

According to the present invention, it is possible to readily positionthe mandibular condyle model in the lateral direction (X-Y direction)and the circumferential direction.

Regarding the configuration according to any one of claims 3 to 9, aninvention according to claim 10 is characterized by further comprisingupper positioning means for regulating the position of the pedestal ofthe maxillary fossa model relative to the upper mounting part.

According to the present invention, it is possible to readily adjust adirection when mounting the maxillary fossa model on the upperbow-shaped part.

Regarding the configuration according to any one of claims 3 to 10, aninvention according to claim 11 is characterized by further comprisinglower positioning means for regulating the position of the pedestal ofthe mandibular condyle model relative to the lower mounting part.

According to the present invention, it is possible to readily adjust adirection when mounting the mandibular condyle model on the lowerbow-shaped part.

Regarding the configuration according to any one of claims 1 to 11, aninvention according to claim 12 is characterized by further comprisingposition adjusting means for laterally adjusting the position of atleast one of the artificial condyle and the artificial articular fossa.

According to the present invention, since a position can be adjusted inthe lateral direction, the positions of the right and left joints of theoccludator can be adjusted according to a distance between the right andleft temporomandibular joints of a target person.

Regarding the configuration according to any one of claims 1 to 12, aninvention according to claim 13 is characterized in that two or morepairs of the mandibular condyle model and the maxillary fossa model areprovided, and a pair of the mandibular condyle model and the maxillaryfossa model is used as the artificial condyle and the artificialarticular fossa according to the shape of the temporomandibular joint ofa person whose impression has been obtain during the fabrication of theupper jaw tooth model.

According to the present invention, it is not necessary to prepare amandibular condyle model and a maxillary fossa model for each targetpatient. If the tendency of temporomandibular joints is identified foreach target patient, a mandibular condyle model and a maxillary fossamodel to be used can be selected from ordinary two-dimensionalradiographs.

Regarding the configuration according to any one of claims 1 to 13, aninvention according to claim 14 is characterized by further comprisingconnecting parts on a pair of lateral positions in the occludator, theconnecting parts connecting the face bow.

An invention according to claim 15 is a face bow which is used for theoccludator according to claim 14 and reproduces the positionalrelationship between a temporomandibular joint and an occlusion plane onthe occludator, characterized in that the face bow comprises a face bowbody having a pair of right and left legs stretching symmetrically, aconnecting part which is provided on an end of each leg and can beconnected to the connecting part of the occludator, and a nose piecewhich is supported by the face bow body and brought into contact with ahollow in the upper part of the nose of a patient, and the nose piececomprises a position adjusting mechanism capable of adjusting a positionat least in the vertical direction and the longitudinal direction withrespect to the face bow body.

According to the present invention, when the face bow is adjusted on astandard plane such as the FH plane, the face bow is supported on thehead of a patient via at least three points of the ends of the right andleft legs and the nose piece. At this point, the nose piece can beadjusted at least in the vertical direction and the longitudinaldirection. Thus, by adjusting the position of the nose piece withrespect to the face bow body, the face bow can be adjusted on thestandard plane while being supported positively on the head of thepatient via at least three points.

Regarding the configuration according to claim 15, an inventionaccording to claim 16 is characterized in that the face bow bodycomprises a level.

According to the present invention, a state of inclination can bereadily confirmed by the level. That is, the face bow can be positivelyleveled and used at the setting of the face bow. In other words, theposition of occlusion in a living body can be reproduced on theoccludator with higher accuracy.

Regarding the configuration according to claim 15 or 16, an inventionaccording to claim 17 is characterized in that the connecting partprovided on the end of the leg is an ear rod which can be inserted intoan external auditory meatus of a patient, and the connecting part of theoccludator is constituted of an insertion hole permitting the insertionof the ear rod.

An invention of claim 18 is characterized in that the face bow body ismade of a material permitting the passage of an X-ray beam, and the facebow body comprises a marking member which is laterally opposed to thecenter of a mandibular condyle of a patient or the vicinity of thecenter in front of the ear rod and is made of a material not permittingthe passage of an X-ray beam, and a supporting member causing the leg tosupport the marking member.

Further, in order to attain the objects, an invention according to claim19 of the present invention provides an occlusion confirming systemcomprising a CT device for photographing a temporomandibular joint of atarget person, a stereolithography machine for forming a solid model ofthe temporomandibular joint on the basis of three-dimensional image dataof the temporomandibular joint specified by image informationphotographed by the CT device, and an occludator including a lowerbow-shaped part for mounting a lower jaw tooth mold, an upper bow-shapedpart for mounting an upper jaw tooth mold, and right and left joints forconnecting the lower bow-shaped part and the upper bow-shaped part,characterized in that the joint comprises an artificial condyle which ismounted on the lower bow-shaped part and protrudes upward and anartificial articular fossa which is mounted on the upper bow-shaped partand is opposed to the artificial condyle from above, at least one of theartificial condyle and the artificial articular fossa is constituted ofthe solid model formed by the stereolithography machine.

According to the present invention, a joint structure identical to anactual temporomandibular joint of a target person can be reproduced onthe occludator.

An invention according to claim 20 provides an occlusion confirmingsystem characterized by comprising an occludator including a lowerbow-shaped part for mounting a lower jaw tooth mold, an upper bow-shapedpart for mounting an upper jaw tooth mold, and right and left joints forconnecting the lower bow-shaped part and the upper bow-shaped part, thejoint being constituted of a mandibular condyle model which isdetachably mounted on the lower bow-shaped part and a maxillary fossamodel which is detachably mounted on the upper bow-shaped part so as tobe vertically opposed to the mandibular condyle model, two or more kindsof mandibular condyle models and maxillary fossa models used on theoccludator, a database for storing information about the two or morekinds of mandibular condyle models and maxillary fossa models, a CTdevice for photographing a temporomandibular joint of a target person,and selecting means for selecting a specific mandibular condyle modeland maxillary fossa model to be mounted on the occludator from the twoor more kinds of mandibular condyle models and maxillary fossa modelswith reference to the database, on the basis of three-dimensional imagedata of the temporomandibular joint specified by image informationphotographed by the CT device.

According to the present invention, a joint structure identical to anactual temporomandibular joint of a target person can be reproduced onthe occludator.

In this case, it is not necessary to provide the stereolithographymachine all the time. Even if image information photographed by the CTdevice is not so preferable, it is only necessary to collect informationenabling the selection of corresponding data in the database. Thus, evenwhen a CT device of low photographing accuracy is used to, for example,reduce a radiation dose, a proper mandibular condyle model and maxillaryfossa model are available for the occludator.

An invention according to claim 21 provides an occlusion confirmingsystem comprising a database for storing three-dimensional image data ofthe two or more kinds of mandibular condyle models and maxillary fossamodels, a CT device for photographing a temporomandibular joint of atarget person, selecting means for selecting a mandibular condyle modeland a maxillary fossa model which are closer to the three-dimensionalshape of the photographed temporomandibular joint among the two or morekinds of mandibular condyle models and maxillary fossa models on thebasis of three-dimensional image data of the temporomandibular jointspecified by image information photographed by the CT device orcharacteristic information and three-dimensional image data in thedatabase, a stereolithography machine for forming the solid model of themandibular condyle model and maxillary fossa model having been selectedby the selecting means, on the basis of the data in the database, and anoccludator including a lower bow-shaped part for mounting a lower jawtooth mold, an upper bow-shaped part for mounting an upper jaw toothmold, and right and left joints for connecting the lower bow-shaped partand the upper bow-shaped part, characterized in that the joint comprisesan artificial condyle which is mounted on the lower bow-shaped part andprotrudes upward and an artificial articular fossa which is mounted onthe upper bow-shaped part and is opposed to the artificial condyle fromabove, the solid model formed by the stereolithography machine is usedas at least one of the artificial condyle and the artificial articularfossa.

According to the present invention, a joint structure identical to anactual temporomandibular joint of a target person can be reproduced onthe occludator.

In this case, even if image information photographed by the CT device isnot so preferable, it is only necessary to collect information enablingthe selection of corresponding data in the database. Thus, even when aCT device of low photographing accuracy is used to, for example, reducea radiation dose, proper mandibular condyle model and maxillary fossamodel are available for the occludator.

When information is transferred from the CT device to thestereolithography machine via communicating means, databases areprovided in both of the CT device and the stereolithography machine.Thus, only identification information such as a corresponding modelnumber in the databases is communicated, thereby considerably reducing avolume of traffic.

Regarding the configuration according to any one of claims 19 to 21, aninvention according to claim 22 is characterized by further comprisingan elastic body for applying an urging force in a direction of bringingthe lower bow-shaped part and the upper bow-shaped part relatively closeto each other.

According to the present invention, the opposed artificial condyle andartificial articular fossa can be kept in contact with each other and asmooth joint movement can be obtained.

Regarding the configuration according to any one of claims 19 to 22, aninvention according to claim 23 is characterized in that the joint isconstituted of an upper joint and a lower joint which are opposed toeach other, the upper joint is constituted of an upper mounting membersupported by the upper bow-shaped part, a maxillary fossa model, andfirst mounting means for detachably mounting the pedestal of themaxillary fossa model on the upper mounting member, and the lower jointis constituted of a lower mounting member fixed on the lower bow-shapedpart, a mandibular condyle model, and second mounting means fordetachably mounting the pedestal of the mandibular condyle model on thelower mounting member.

According to the present invention, the maxillary fossa model and themandibular condyle model can be replaceable.

Regarding the configuration according to claim 23, an inventionaccording to claim 24 is characterized in that the first mounting meansis constituted of a male screw part formed on the upper mounting member,a cylindrical member having a female screw formed in an inner surface,the female screw enabling to be screwed to the male screw, and an innerflange which is formed integrally with the cylindrical member, forms ahole permitting the passage of the maxillary fossa model, and can makecontact with the periphery of the pedestal of the maxillary fossa model,and the periphery of the pedestal of the maxillary fossa model issandwiched between the upper mounting member and the inner flange byscrewing the female screw to the male screw.

According to the present invention, the maxillary fossa model can beattached and detached with ease.

Regarding the configuration according to claim 23 or 24, an inventionaccording to claim 25 is characterized in that the second mounting meansis constituted of a male screw part formed on the lower mounting member,a cylindrical member having a female screw formed in an inner surface,the female screw enabling to be screwed to the male screw, and an innerflange which is formed integrally with the cylindrical member, forms ahole permitting the passage of the mandibular condyle model, and canmake contact with the periphery of the pedestal of the mandibularcondyle model, and the periphery of the pedestal of the mandibularcondyle model is sandwiched between the lower mounting member and theinner flange by screwing the female screw to the male screw.

According to the present invention, the mandibular condyle model can beattached and detached with ease.

Regarding the configuration according to claim 23 or 25, an inventionaccording to claim 26 is characterized in that the first mounting meanscomprises a ring-shaped part which is formed on an end of the uppermounting member and has an inner concave part permitting the insertionof the pedestal of the maxillary fossa model, and a fixing screw whichcan laterally penetrate the ring-shaped part while being connected tothe ring-shaped part by screwing, and has an end capable of beingscrewed inward or in contact with the side of the pedestal of themaxillary fossa model.

According to the present invention, the maxillary fossa model can beattached and detached with ease.

Regarding the configuration according to claim 23 or 24, an inventionaccording to claim 27 is characterized in that the second mounting meanscomprises a ring-shaped part which is formed on an end of the lowermounting member and has an inner concave part permitting the insertionof the pedestal of the mandibular condyle model, and a fixing screwwhich can laterally penetrate the ring-shaped part while being connectedto the ring-shaped part by screwing, and has an end capable of beingscrewed inward or in contact with the side of the pedestal of themandibular condyle model.

According to the present invention, the mandibular condyle model can beattached and detached with ease.

Regarding the configuration according to any one of claims 23 to 27, aninvention according to claim 28 is characterized by further comprisingupper positioning means for regulating the position of the pedestal ofthe maxillary fossa model relative to the upper mounting part.

According to the present invention, it is possible to readily adjust adirection when mounting the maxillary fossa model on the upperbow-shaped part.

Regarding the configuration according to any one of claims 23 to 28, aninvention according to claim 29 is characterized by further comprisinglower positioning means for regulating the position of the pedestal ofthe mandibular condyle model relative to the lower mounting part.

According to the present invention, it is possible to readily adjust adirection when mounting the mandibular condyle model on the upperbow-shaped part.

Regarding the configuration according to any one of claims 19 to 29, aninvention according to claim 30 is characterized by further comprisingposition adjusting means for laterally adjusting the position of atleast one of the artificial condyle and the artificial articular fossa.

According to the present invention, since a position can be adjusted inthe lateral direction, the positions of the right and left joints of theoccludator can be adjusted according to a distance between the right andleft temporomandibular joints of a target person.

Regarding the configuration according to any one of claims 19 to 30, aninvention according to claim 31 is characterized by further comprising aface bow including a face bow body which is used for reproducing thepositional relationship between the temporomandibular joint and anocclusion plane on the occludator and has a pair of right and left legsstretching symmetrically, characterized in that at least the right andleft legs are made of a material permitting the passage of a light beamused in the CT device, and at least one marking member is provided on anend of each of the right and left legs, the marking member being made ofa material not permitting the passage of the light beam.

The present invention is preferable when a local irradiation CT deviceis used, which does not photograph right and left temporomandibularjoints at the same time in consideration of a radiation dose and so on.

According to the present invention, the marking member is alsophotographed close to an image of a temporomandibular joint during thephotographing of the CT device. Thus, it is possible to calculate adistance between a temporomandibular joint hidden in a living body andthe adjacent marking member, that is, a distance between an end of theface bow and an adjacent temporomandibular joint from the image data.

Further, a distance between right and left temporomandibular joints canbe determined by determining a distance between the right and left endsof the face bow, so that the right and left joints on the occludator canbe set according to a distance between actual temporomandibular joints.

Regarding the configuration according to claim 31, an inventionaccording to claim 32 is characterized in that the face bow comprises anose piece which is supported by the face bow body and brought intocontact with a hollow in the upper part of the nose of a patient, andthe nose piece comprises a position adjusting mechanism capable ofadjusting a position at least in the vertical direction and thelongitudinal direction with respect to the face bow body.

According to the present invention, by adjusting the position of thenose piece with respect to the face bow body, the setting position ofthe face bow body can be readily adjusted on a standard plane such asthe FH plane.

Regarding the configuration according to claim 31 or 32, an inventionaccording to claim 33 is characterized in that the face bow bodycomprises a level.

According to the present invention, a degree of levelness of the facebow body can be visually recognized with ease by the level. That is, theposition of occlusion in a living body can be reproduced on theoccludator with higher accuracy.

Regarding the configuration according to any one of claims 31 to 33, aninvention according to claim 34 is characterized in that the markingmember is disposed on a position presumed to be laterally opposed to thecenter of the mandibular condyle of a patient.

Regarding the configuration according to any one of claims 31 to 34, aninvention according to claim 35 is characterized by further comprisingan ear rod on an end of the leg in the face bow, the ear rod beinginserted into an external auditory meatus of a patient, and each of theright and left sides of the occludator has an insertion hole for theinsertion of the ear rod.

Regarding the configuration according to claims 31 to 34, an inventionaccording to claim 36 comprising a headgear fixed on the head of atarget person, characterized in that the head gear comprises right andleft connecting parts for temporarily connecting the right and left endsof the face bow and connection position adjusting means for adjustingthe position of the connecting part to a predetermined position.

According to the present invention, the right and left ends of the facebow can be set to desired positions. The position of the connecting partis preferably set on lateral position of the center of a targetmandibular condyle (lateral position on the same horizontal plane as thecenter of the mandibular condyle).

The position of the connecting part is varied according to the size of ahead, etc., and can be adjusted by the connection position adjustingmeans.

Regarding the configuration according to claim 36, an inventionaccording to claim 37 is characterized in that the headgear comprisesfixing means for temporarily fixing the headgear to the CT device.

According to the present invention, the headgear is temporarily fixed onthe CT device, so that the head is fixed during the photographing of theCT device and the setting position is not varied.

Regarding the configuration according to any one of claims 19 to 37, aninvention according to claim 38 is characterized by comprising adatabase for storing ideal model information about a temporomandibularjoint condyle, is characterized by further comprising data correctingmeans for correcting three-dimensional data on the temporomandibularjoint condyle specified by image information photographed by the CTdevice such that the contour of the temporomandibular joint condylespecified by the image information photographed by the CT device isidentical to a contour protruding closer to an ideal model, when acomparison is made between the coutour of the temporomandibular jointcondyle specified by the image information photographed by the CT deviceand the corresponding ideal model on the database and it is decided thatthe temporomandibular joint condyle wears more than a predetermineddegree.

According to the present invention, when the top of an actual mandibularcondyle wears more than a predetermined degree, a correction is made toa protrusion of a mandibular condyle presumed to be close to a healthycondition, occlusion close to the healthy condition is reproduced on theoccludator, and prostheses are constructed according to the occlusion.Thus, it is possible to obtain occlusion close to the healthy state in aliving body and the temporomandibular joint may be restored to a normalcondition.

Further, three-dimensional data may be stored at a younger age and aprotrusion may be corrected according to the stored data.

An invention according to claim 39 provides a temporomandibular jointreproducing system characterized by comprising a CT device forphotographing a temporomandibular joint of a target person, and astereolithography machine for forming a solid model of atemporomandibular joint on the basis of three-dimensional data of thetemporomandibular joint specified by image information photographed bythe CT device.

According to the present invention, it is possible to fabricate a solidmodel of an actual temporomandibular joint.

Regarding the configuration according to claim 39, an inventionaccording to claim 40 is characterized by further comprising a face bowincluding a face bow body which is used for reproducing the positionalrelationship between the temporomandibular joint and an occlusion planeon the occludator and has a pair of right and left legs stretchingsymmetrically, characterized in that at least the right and left legsare made of a material permitting the passage of a light beam used inthe CT device, a marking member is provided on an end of each of theright and left legs on a position presumed to be laterally opposed tothe center of the mandibular condyle of a patient, the marking memberbeing made of a material not permitting the passage of the light beam,and a forming area for stereolithography is specified according to theposition of the photographed marking member.

Regarding the configuration according to claim 39 or 40, an inventionaccording to claim 41 characterized by comprising a data conversionsection for converting three-dimensional image data of thetemporomandibular joint specified by the image information photographedby the CT device, into two-dimensional contour image data of multiplelayers for stereolithography, and transmitting means for transmittingthe two-dimensional contour image data of multiple layers, which havebeen converted by the data conversion section, to the stereolithographymachine via communication means.

According to the present invention, two-dimensional contour image dataof multiple layers used for stereolithography is transmitted instead ofthree-dimensional image data, thereby reducing an amount oftransmission.

Regarding the configuration according to claim 41, an inventionaccording to claim 42 is characterized in that the two-dimensionalcontour image data transmitted by the transmitting means is coordinatedata of two or more points for specifying a two-dimensional contour of acorresponding cross section.

According to the present invention, a plurality of coordinates forspecifying a contour are transmitted as the two-dimensional contourimage data, instead of raw data such as binary data, thereby furtherreducing the amount of transmission.

A supplementary explanation will be given on the occludator of thepresent invention and the occludator used for the present invention.

It is expected that the fabrication of the maxillary fossa and themandibular condyle of a patient and the reproduction of athree-dimensional movement of a mandibular movement would be extremelyuseful for the fabrication of a large prosthesis as well as a smallprosthesis. That is, moderate satisfaction so far is turned to greatsatisfaction by the present invention and effectiveness is provided forthe patient.

Another suggestion will be made below on a condyle path. A condyle pathguidance is guided by a maxillary fossa and a mandibular condyle in amanner unique to a patient and cannot be freely changed by an operator.Conventionally this guidance has been regarded as the most importantguidance of mandibles. For a person who has lost upper and lower teeth,an occlusion pattern and a cusp angle of teeth (artificial teeth) aredetermined by the condyle path guidance. When a small condyle path isadjusted for an occludator, in the case of a larger movement, cuspsinterfere with each other and thus the occludator may not act as meansfor providing preferred occlusion. Such a problem is avoidable in theadoption of the present invention.

As the conventional occludator, when a joint is constituted of a lineararticular fossa and a spherical mandibular condyle and prostheses arefabricated, interference (full denture or a number of lost teeth) mayoccur in a lateral movement. Such an interference is likely to cause atemporomandibular arthrosis and break teeth. In contrast to theconventional art, the present invention makes it possible to reproduce atemporomandibular joint of each patient in a three-dimensional manner,thereby readily preventing the interference.

Further, the present invention can reproduce an actual temporomandibularjoint on the occludator, that is, a state of a temporomandibular jointin a living body can be extracted to the outside. Thus, the presentinvention is applicable in various fields.

An artificial arm, an artificial leg, or an artificial eye is effectivein terms of appearance, whereas original functions cannot be exercised.In this sense, the present invention is advantageous because functionscan be reproduced. Therefore, occlusion can be analyzed. Unlike theconventional art, prostheses are fabricated without the need foradjusting various angles. That is, since an actual temporomandibularjoint is reproduced, it is expected that the present invention is usefulfor preventing occlusion interference, premature contact, bruxism, adisplacement of a jaw, and an internal deformation of atemporomandibular joint.

A temporomandibular joint is different in form and function from otherjoints, and thus the characteristic causes of diseases and theprogresses of diseases have been hardly clarified due to, for example,difficulty in sampling the materials. Even in the absence of an organicchange, it is extremely rare to find completely symmetrical mandibularcondyles. Unlike the conventional art, the occludator of the presentinvention reproduces a size and a form almost equal to actual ones(e.g., an error is 50 μm). Thus, the present invention is useful for thefollowing unexplained diseases: a birth defect on a jaw, growthabnormality, inflammation, an external wound, ankylosis oftemporomandibular joint, and a metabolic disease. As described above,the present invention is a ray of hope in clinical diagnosis, treatment,and epidemiography on temporomandibular arthrosis and contributes totreatment and the decision of a cause and progress of a disease.

Moreover, the conventional occludator cannot express a change of anarticular fossa and a mandibular condyle between ages. Products havebeen fabricated only by a linear articular fossa and a contact shapedlike a ball. However, the occludator of the present invention can handlea regressive change. A proper load should be applied to an articularfossa and a mandibular condyle all the time. The occludator of thepresent invention can respond to the need.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear view showing an occludator according to Embodiment 1 ofthe present invention;

FIG. 2 is a diagram showing an occludator taken along line A-A of FIG. 1according to Embodiment 1 of the present invention;

FIG. 3 is a partial sectional view showing the mounting structure of amandibular condyle model according to Embodiment 1 of the presentinvention;

FIG. 4 is a top view showing the lower mounting part of a coil springaccording to Embodiment 1 of the present invention;

FIG. 5 is a schematic structural diagram showing an occlusion confirmingsystem according to Embodiment 1 of the present invention;

FIG. 6 is a diagram showing a photographing area according to Embodiment1 of the present invention;

FIG. 7 is a diagram showing an example of a tomogram duringstereolithography according to Embodiment 1 of the present invention;

FIG. 8 is a diagram for explaining uniaxial-multidirectional processingaccording to Embodiment 1 of the present invention;

FIG. 9 is a plan view showing a face bow according to Embodiment 1 ofthe present invention;

FIG. 10 is a side view showing the face bow according to Embodiment 1 ofthe present invention;

FIG. 11 is a side view showing a headgear according to Embodiment 1 ofthe present invention;

FIG. 12 is a top view showing the headgear according to Embodiment 1 ofthe present invention;

FIG. 13 is a front view showing the headgear according to Embodiment 1of the present invention;

FIG. 14 is a diagram for explaining a vertical position adjustingmechanism according to Embodiment 1 of the present invention;

FIG. 15 is a side view showing the relationship between the headgear andthe face bow according to Embodiment 1 of the present invention;

FIG. 16 is a plan view showing the relationship between the headgear andthe face bow according to Embodiment 1 of the present invention;

FIG. 17 is a partially enlarged view showing the relationship betweenthe headgear and the face bow according to Embodiment 1 of the presentinvention;

FIG. 18 is a front view showing the relationship between a markingmember and a mandibular condyle according to Embodiment 1 of the presentinvention;

FIG. 19 is a front view showing the relationship between the markingmember and a mandibular condyle model according to Embodiment 1 of thepresent invention;

FIG. 20 is a side view showing the relationship between the occludatorand the face bow according to Embodiment 1 of the present invention;

FIG. 21 is a plan view showing the relationship between the occludatorand the face bow according to Embodiment 1 of the present invention;

FIGS. 22A and 22B show another examples of the mounting of the model,FIG. 22A is a plan view, and FIG. 22B is a side view;

FIG. 23 is a plan view showing another example of the mounting of themodel;

FIGS. 24A and 24B show another examples of the mounting of the model,FIG. 24A is a plan view, and FIG. 24B is a side view;

FIG. 25 is a plan view showing a face bow according to Embodiment 2 ofthe present invention;

FIG. 26 is a diagram taken from arrow A of FIG. 25;

FIG. 27 is a diagram taken from arrow B of FIG. 25;

FIG. 28 is a diagram showing another example of a protrusion 107;

FIG. 29 is a diagram showing a nose piece;

FIG. 30 is a diagram showing that the nose piece is mounted on ahorizontal bar;

FIG. 31 is a schematic diagram showing the relationship between a headand the face bow;

FIG. 32 is a schematic diagram showing a connection of the face bow andthe occludator;

FIG. 33 is a plan view showing the face bow according to Embodiment 2 ofthe present invention;

FIG. 34 is a diagram taken from arrow A of FIG. 33;

FIG. 35 is a diagram taken from arrow B of FIG. 33;

FIG. 36 is a side view showing an example of a connection to theoccludator;

FIG. 37 is a plan view showing another example of a mechanism foradjusting a distance between right and left leg bodies;

FIG. 38 is a front view showing another example of a mechanism foradjusting a distance between right and left leg bodies;

FIG. 39 is a diagram for explaining a correction example of the shape ofthe mandibular condyle;

FIG. 40 is a schematic diagram showing the relationship between an imagepickup area and a forming area;

FIG. 41 is a schematic diagram showing the relationship between theimage pickup area and the forming area;

FIG. 42 is a schematic diagram showing the relationship between theimage pickup area and the forming area;

FIG. 43 is a schematic diagram showing the relationship between theimage pickup area and the forming area;

FIG. 44 is a schematic diagram showing the relationship between theimage pickup area and the forming area; and

FIGS. 45A and 45B are diagrams for explaining a correction of aconcentration.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 of the present invention will be described below inaccordance with the accompanying drawings.

First, the following will discuss the configuration of an occludator Kused for the present system.

As shown in FIGS. 1 and 2, the occludator K of the present embodiment isconstituted of an upper bow-shaped part 1, a lower bow-shaped part 2, ajoint 3 for connecting the upper bow-shaped part 1 and the lowerbow-shaped part 2, and an incisal pin 4. To enhance understanding, amandibular condyle model 14 and a maxillary fossa model 22, which arevertically opposed to each other, are not in contact with each other insome drawings below. In reality, the models are in contact with eachother (contact state) or an elastic sheet material (not shown, thematerial is made of a material such as silicon and is preferably equalin elastic modulus to an articular disk) equal in thickness to a gapbetween joints is interposed between the models. Further, to enhanceunderstanding, some parts are omitted in the drawings when necessary aslong as no ambiguity occurs.

The lower bow-shaped part 2 is constituted of a lower bow-shaped partbody 5 for mounting a lower jaw tooth mold (not shown) and a gate part 6which rises upward from the rear of the lower bow-shaped part body 5.

The upper bow-shaped part 1 is constituted of an upper bow-shaped partbody 7 for mounting an upper jaw tooth mold (not shown) and jointmounting parts 8 which are connected on the right and left to the rearof the upper bow-shaped part body 7. The connecting configuration of theupper bow-shaped part body 7 and the joint mounting parts 8 will bediscussed below. A connection is made as follows: an insertion hole 9,which laterally penetrates and is rectangular in cross section, isformed in the rear of the upper bow-shaped part body 7, and bars 10,which protrude respectively from the joint mounting parts 8 and arerectangular in cross section, are inserted into the insertion hole 9.Then, fixing screws 11 are screwed into tapped holes which verticallypenetrate in the rear of the upper bow-shaped part body 7 and the endsof the fixing screws 11 are brought into contact with the sides of thebars 10, so that the joint mounting parts 8 on the right and left arefixed to the upper bow-shaped part 1. Further, an amount of insertion ofthe right and left bars 10 into the insertion hole 9 is adjusted, sothat a distance can be adjusted between the right and left jointmounting parts 8. In this case, the bars 10 and the insertion hole 9 areshaped like rectangles. This is because the upper bow-shaped part body 7can be positively held in a horizontal direction with respect to thejoint mounting parts 8.

As shown in FIG. 1, the joint mounting parts 8 on the right and left areeach shaped like a letter L in front view (as a matter of course, a boxor the like with an open bottom is also applicable). The joint mountingpart 8 is constituted of a horizontal part 8A which stretcheshorizontally along the axis of the bar 10 and a vertical part 8B whichvertically stretches downward from the outer end of the horizontal part8A.

Further, as shown in FIG. 1, the joints 3 on the right and left areprovided between the gate part 6 and the right and left joint mountingparts 8. The gate part 6 and the joint mounting parts 8 are verticallyopposed to each other.

The joint 3 is configured such that a lower joint 3A mounted on the gatepart 6 and an upper joint 3B mounted on the joint mounting part 8 arevertically opposed to each other.

As shown in FIGS. 1 and 3, the lower joint 3 is constituted of a lowermounting member 13, the mandibular condyle model 14, and a mounting nut15 constituting a cylindrical member. The lower mounting member 13 isconstituted of a cylindrical member and is supported by a horizontalpart 6A of the gate part 6 so as to move only laterally along the uppersurface of the horizontal part 6A. The mechanism movable only in thelateral direction is configured by providing, e.g., a guide groove 16which laterally stretches on the lower surface of the gate part 6 and aguide 17 which is fit into and guided by the guide groove 16 on thelower surface of the lower mounting member 13.

Moreover, the lower mounting member 13 has a female tapped hole 18laterally penetrating in parallel with the horizontal part 8A. The shaftof a screw 19 is screwed into the female tapped hole 18. The screw 19 isrotationally supported with a bearing or the like by a rising part 20provided on the horizontal part 8A. Forward/reverse rotations of thescrew 19 can adjust the position of the lower mounting member 13 in thelateral direction. The end of the shaft of the screw 19 is alsorotationally supported by the horizontal part 8A.

As shown in FIG. 3, the end of the lower mounting member 13 serves as acylindrical part 13A having a vertical axis. A male screw is cut on theperiphery (outer periphery) of the cylindrical part 13A to form a malescrew part. Further, the end face of the lower mounting member 13 hastwo positioning holes 13 a.

The mandibular condyle model 14 is constituted of a model body 14 a anda disk-like pedestal 14 b which is connected to the base of the modelbody 14 a. Two pins 14 c protrude downward from the lower end face ofthe pedestal 14 b so as to be inserted into the positioning holes 13 a.As will be described later, the mandibular condyle model 14 is formed bystereolithography. In this case, the positioning holes 13 a and the pins14 c constitute lower positioning means.

Further, the mounting nut 15 is a member shaped like a cylindrical cap.A female screw screwed to the male screw is formed on the inner surfaceof the mounting nut 15 and an inward flange 15A is provided on the upperopening of the mounting nut 15. The opening formed by the inward flange15A is large enough to freely insert the model body 14 a. The opening isset smaller in diameter than the pedestal 14 b, so that the lowersurface of the inward flange 15A can be vertically opposed to the uppersurface of the outer periphery of the pedestal 14 b.

Then, as shown in FIG. 3, in a state in which the pedestal 14 b isbrought into contact with the end face of the lower mounting member 13while positioning is performed by the positioning holes and the pins 14c, the mounting nut 15 is put from above and is screwed and fastened tothe cylindrical part 13A of the lower mounting member 13, so that theouter periphery of the pedestal 14 b is vertically sandwiched betweenthe end face of the upper mounting member and the lower surface of theinward flange 15A. Thus, the mandibular condyle model 14 is mounted onthe horizontal part 8A of the gate part 6.

The upper joint 3 is identical in configuration to the lower joint 3 andis constituted of an upper mounting member 21, the maxillary fossa model22, and a mounting nut 23 constituting a cylindrical member. The uppermounting member 21 is supported by the horizontal part 8A so as to moveonly in the lateral direction along the lower surface of the horizontalpart 8A of the joint mounting part 8. Further, a screw rotationallysupported by the vertical part 8B is screwed into the upper mountingmember 21. Forward/reverse rotations of the screw can adjust theposition of the upper mounting member 21 in the lateral direction.

The end of the upper mounting member 21 forms a cylindrical part havinga vertical axis. A male screw is cut on the periphery of the cylindricalpart to form a male screw part. Further, the end face of the lowermounting member has two positioning holes.

The maxillary fossa model 22 is constituted of a model body and adisk-like pedestal which is connected to the base of the model body.Pins protrude upward from the pedestal so as to be inserted into thepositioning holes. As will be described later, the maxillary fossa model22 is formed by stereolithography. In this case, the positioning holesand the pins constitute upper positioning means.

The mounting nut 23 is a member shaped like a cylindrical cap. A femalescrew screwed to the male screw is formed on the inner surface of themounting nut 23 and an inward flange is provided on the lower opening ofthe mounting nut 23. The opening formed by the inward flange is largeenough to freely insert the model body. The opening is set smaller indiameter than the pedestal, so that the upper surface of the inwardflange can be opposed to the outer periphery of the pedestal. Then, in astate in which the pedestal is brought into contact with the end face ofthe upper mounting member 21, the mounting nut 23 is put from below andis screwed and fastened to the end of the upper mounting part, so thatthe outer periphery of the pedestal is vertically sandwiched between theend face of the upper mounting part and the inward flange. Thus, themaxillary fossa model 22 is mounted on the horizontal part 8A.

In this case, on the part of the insertion hole 9 and the right and leftbars 10 and the part of the female tapped hole 18 and the screw 19, thelateral position adjusting part constitutes position adjusting means.The two stages illustrate the reproduction of a distance between markingmembers (described later) and the reproduction of a distance of closestapproach (described later).

A coil spring 30, which constitutes an elastic body and has a verticalaxis, is disposed at the front of the right and left joints 3 and at thecenter in the lateral direction. The coil spring 30 has an upper endfixed to the upper bow-shaped part 1 and a lower end detachably mountedon a protrusion 31 protruding from the gate part 6. As shown in FIG. 4,a spring mounting part 32 is notched on a side of the protrusion 31. Thespring 30 is inserted from the side, so that the spring 30 can bedetachably mounted.

In this case, the number of the springs 30 is not limited to one at thecenter. Two springs may be disposed symmetrically. Springs may beprovided on three or more points. The spring force of the spring canpreferably reproduce the elasticity and so on of muscle in somepositions.

As shown in FIG. 2, the incisal pin 4 protrudes downward from the frontend of the upper bow-shaped part 1, and the end of the incisal pin 4 isin contact with the front end of the lower bow-shaped part 2. A lengthof the incisal pin 4 from the upper bow-shaped part 1 can be adjusted.

Thus, the upper bow-shaped part 1 is supported by the lower bow-shapedpart 2 on three points of the left and right joints 3 and the incisalpin 4, and the maxillary fossa model 22 can be relatively kept incontact with the mandibular condyle model 14 from above by the coilspring 30.

Reference numeral 33 in FIG. 2 denotes a catching part for catching thecenter of the face bow F. The occludator K is set so as to arrange thechain line of FIG. 2 along the horizontal direction.

The following will describe the fabrication of a solid model serving asthe maxillary fossa model 22 and the mandibular condyle model 14, whichare used in the occludator K.

As shown in FIG. 5, the device configuration for fabricating the solidmodel is constituted of an X-ray CT device 40 and a stereolithographymachine 50.

The X-ray CT device 40 photographs a temporomandibular joint area of atarget patient that is shown in FIG. 6 and calculates the stereographicdata of the temporomandibular joint area from photographic information(image information).

As shown in FIG. 7, from three-dimensional image data calculated andoutputted by the X-ray CT device 40, the stereolithography machine 50cuts out tomograms (binary image) of two or more layers along apredetermined axis (Z axis), determines the contours of thetemporomandibular joint from the tomograms, and sequentially overlaysthe contours while performing photo-curing in the contours, so that asolid model is constructed. Any method is applicable as long as themethod belongs to generally known stereolithography.

The solid model may be divided into an articular fossa model and acondyle model after forming the articular fossa model and the condylemodel together as the solid model. Alternatively, an articular fossamodel and a condyle model may separately undergo stereolithography. Thefollowing will describe an example in which the articular fossa modeland the condyle model are formed as one solid model.

Regarding the X-ray CT device 40, for example, a local irradiation X-rayCT imaging apparatus disclosed in WO00/57789 is preferable in which apredetermined local area is used as a photographic area. Thephotographic area is smaller than that of the ordinary medical CT device40, thereby reducing a dose of radiation to a patient.

The local radiation X-ray CT imaging apparatus at least comprises arotary arm 40C which opposes an X-ray generator 40A and atwo-dimensional X-ray image sensor 40B to each other via thephotographic area, position adjusting means which matches the rotatingcenter of the rotary arm 40C and the center of a temporomandibular jointarea serving as a subject, rotating means which rotates the rotary arm40C while locally emitting an X-ray cone beam from the X-ray generator40A, the X-ray cone beam passing through only the temporomandibularjoint area all the time, and calculating means 40D which calculates, byback projection, X-ray projection image information of thetemporomandibular joint area obtained by the two-dimensional X-ray imagesensor 40B by means of the X-ray cone beam, and calculatesthree-dimensional projection data (three-dimensional image data)composed of three-dimensional distribution information on an X-rayabsorption coefficient of the temporomandibular joint area. In FIG. 5,reference numeral 40E denotes an example of a data storage area.

The local irradiation X-ray CT device 40 successively photographs, as alocal photographic area (a cylindrical area shown in FIG. 6), one of theright and left temporomandibular joints 3 of a target patient,calculates three-dimensional image data on the photographic area(temporomandibular joint area) from a plurality of pieces of imageinformation obtained by photographing, and records the three-dimensionalimage data in the data storage area.

The present embodiment comprises a uniaxial-multidirectional processingsection 51 which performs uniaxial-multidirectional processing onthree-dimensional image data calculated by the X-ray CT device 40.

The uniaxial multidirectional processing section 51 is a noise removingsection which lowers a level by temporarily cutting thethree-dimensional image data into two-dimensional images along two ormore directions, removes noise on the two-dimensional images, andperforms rearrangement again in a three-dimensional manner. That is,when three-dimensional image data is cut into two-dimensional images,the uniaxial-multidirectional processing section cuts, e.g., thethree-dimensional image data into consecutive two-dimensional imagesalong a plurality of different directions, e.g., along the X-axisdirection and the Y-axis direction, and rearranges the consecutiveimages along the two directions in a three-dimensional manner to reeditthe three-dimensional image data. The above explanation described theexample where cutting is performed in two directions to lower a level.As shown in FIG. 8, it is preferable to use and rearrangetwo-dimensional images cut along 16 directions or more orthogonal to theZ axis.

With this uniaxial-multidirectional processing, duringstereolithography, surface information lost by cutting into consecutivetwo-dimensional images along one direction (e.g., Z axis) isinterpolated by two-dimensional images cut in other directions and isrearranged into three-dimensional image data with higher accuracy. As aresult, also regarding a solid model of a temporomandibular joint thatis formed by stereolithography from two-dimensional images having beencut along the Z axis, it is possible to obtain a solid model of atemporomandibular joint with more accurate stereolithography. The noiseremoving method of the three-dimensional image data is not limited tothe uniaxial-multidirectional processing. Moreover, smoothing may beperformed during stereolithography.

As described above, when obtaining three-dimensional image data on atarget temporomandibular joint from the X-ray CT device 40, thestereolithography machine 50 determines consecutive two-dimensionalsectional data (binary tomograms) along the Z axis from thethree-dimensional image data, performs photo-curing to obtain thetwo-dimensional contours of the two-dimensional sectional data, andrepeatedly overlays the contours, so that a resin solid model of atemporomandibular joint is fabricated. In this configuration, thedisk-like pedestal 14 b is integrally formed on the connecting portion(base) of the mandibular condyle model 14 and the articular fossa modelin each solid model, and the protrusions for positioning are formed onthe pedestal 14 b as described above.

When the mandibular condyle model 14 and the temporomandibular jointfossa model are formed integrally, a gap corresponding to the joint diskis formed between the joints so as to prevent the mandibular condylemodel 14 and the temporomandibular joint fossa model from being incontact with each other, and one or more supports (columns, etc.) areinterposed between the joints vertically opposed to each other, so thatthe models are formed while maintaining the gap. For example, two orthree columns with a diameter of about 2 to 3 mm can sufficiently act asthe supports.

In the device configuration shown in FIG. 5, considering that theinstallation position of the X-ray CT device 40 and the installationposition of the stereolithography machine 50 are separated from eachother, the example is illustrated where three-dimensional image datacalculated by the X-ray CT device 40 or consecutive two-dimensionalimage data along the Z axis is transmitted via communication means suchas the Internet. Reference numerals 60 and 61 illustrate a transmitterand a receiver.

In this case, photographing and stereolithography of the X-ray CT device40 are separately performed on the right and left temporomandibularjoints 3.

Then, as shown in FIG. 1, the mandibular condyle model 14 and themaxillary fossa model 22, which are formed by stereolithography, aremounted on the joints 3 of the occludator K.

The solid model is obtained by stereolithography before the separationof the mandibular condyle model 14 and the maxillary fossa model 22which are vertically connected to each other.

That is, in order to match a distance between the centers of thecondyles of mandibular condyle models 14 mounted on the right and leftof the occludator K with an actual distance between the right and lefttemporomandibular joint condyles of a patient, an amount of insertion ofthe right and left bars 10 is adjusted relative to the insertion hole 9,and the positions of the mandibular condyle models 14 and the maxillaryfossa models 22 on the right and left are adjusted relative to thehorizontal parts 8A by forward/reverse rotations of the screws.

The constructed solid model is mounted in a state in which themandibular condyle model 14 and the maxillary fossa model 22 areintegrally formed. Thus, for example, position adjustment is made suchthat the pins 14 c are inserted into the positioning holes 13 a of thelower mounting member on the side of the gate part 6 of the lowerbow-shaped part 2 and are temporarily mounted, the position of the uppermounting member 21 is adjusted, and the pins on the side of themaxillary fossa model 22 of the solid model are inserted into thecorresponding positioning holes of the upper mounting member.Thereafter, the mandibular condyle model 14 and the maxillary fossamodel 22 are separated from each other and are fixed by the mountingnuts 15 and 23, respectively. In the case of a mechanism where screwsare in contact with each other and are fixed (described later), fixingto the mounting members can be completed before the separation of themandibular condyle model 14 and the maxillary fossa model 22.

The mandibular condyle model 14 and the maxillary fossa model 22 aremounted in the occludator K while being integrated with each other, andthen the mandibular condyle model 14 and the maxillary fossa model 22are separated from each other. The configuration is not limited to theabove. The mandibular condyle model 14 and the maxillary fossa model 22may be separated from each other before being mounted in the occludatorK. However, when the models are separated after being mounted in theoccludator K, it is possible to faithfully reproduce the positionalrelationship between the temporomandibular joint condyle and thetemporomandibular joint fossa vertically while upper and lower teethocclude each other.

Besides, the spring 30 having a vertical axis is temporarily removedwhen the mandibular condyle model 14 and the maxillary fossa model 22are mounted in the occludator K.

The following will describe a headgear H and the face bow F which aresuitable for readily adjusting the right and left positions of theoccludator K with high accuracy.

First, the face bow F will be discussed below.

As shown in FIGS. 9 and 10, the basic configuration is similar to thatof the conventional face bow F. Two legs 70 on the right and left areplaty members which are opposed to each other so as to rotate almostalong a horizontal plane. As with the conventional face bow, the facebow F is provided with a nose piece 71 which is in contact with a hollowin the upper part of the nose of a patient and a bite fork 72 which isbitten by the patient. The positions of the nose piece 71 and the bitefork 72 can be adjusted in the vertical and longitudinal directions withrespect to the face bow F.

The face bow F is mainly characterized as follows:

The body of the face bow F is made of a radiolucent material and amaterial of predetermined strength, e.g., duralumin, an acrylic sheet, abaking plate, fiber reinforced plastics, and so on. A transparentmaterial is more preferable.

A marking member 75 for positioning a condyle is mounted on the end of astick-like insertion part 74 protruding from the end of each of theright and left legs 70. The marking member 75 is made of a material notpermitting the passage of X-ray beams, e.g., a stainless ball and so on.

A level 76 for checking the degree of levelness of the face bow F ismounted.

The configuration of the face bow F shown in FIG. 9 comprises a centralplate 77 stretching in the lateral direction and the right and left legs70 which are connected to the right and left ends of the center plate 77so as to rotate about vertical axes. Further, on the sides of thecentral plate, the right and left legs 70 have nut bodies 78 which aremounted so as to rotate about the vertical axes. A threaded rod 79having an axis in the lateral direction is screwed into the right andleft nut bodies 78. A distance between the right and left legs 70 can beadjusted by forward/reverse rotations of the threaded rod 79.

Further, ends 70 a of the right and left legs 70 can also rotate aboutthe vertical axes, and the marking members 75 are fixed on the ends ofprotrusions formed on the ends of the legs 70. The protrusionsconstitute a connecting part on the side of the face bow F.

Moreover, the nose piece 71 and the bite fork 72 are supported by thehorizontal plate 77. The front side and back side of the U-shaped partof the bite fork 72 are serrated and thus a material for samplingocclusion can readily stick to the front and back sides.

The headgear H will be discussed below. As shown in FIGS. 11 to 13, thehead gear H comprises a headgear body 81 to be mounted on the head of apatient. The top of the headgear body 81 is flattened, a slider 82 issupported so as to move only to the front and back of the top, and alongitudinal adjustment screw 83 rotationally supported on the headgearbody 81 is screwed into the slider 82. Moreover, the longitudinaladjustment screw 83 is turned in the forward/reverse direction, so thatthe slider 82 moves forward and backward to adjust a position in thelongitudinal direction.

Further, bars 84 stretch laterally from the slider 82. The bars 84 areinserted into an insertion hole provided in the slider 82 and an amountof lateral protrusion can be adjusted according to an amount ofinsertion. The end of a screw 85 makes a contact so as to fix the bar 84with a predetermined length.

Moreover, a face bow F mounting body 86 stretching downward is fixed onthe end of the bar 84. A face bow F insertion hole 87 constituting aconnecting part is provided on the end of the face bow F mounting body86. As shown in FIG. 14, the position of a portion 88 of the face bow Finsertion hole 87 can be vertically adjusted by a screw mechanism.

Further, the rear of the headgear body 81 comprises a fixing part 89 forfixing the headgear H to the frame or the like of the X-ray CT device40. The fixing part 89 is constituted of a hook mechanism, a screwmechanism, and so on.

The following will discuss the use of the headgear H and the face bow F.

First, when the temporomandibular joint 3 is photographed using theX-ray CT device 40 as shown in FIG. 5, the headgear H is mounted on thehead of a patient and the headgear H is fixed on the X-ray CT device 40.The headgear H is fixed on the X-ray CT device 40 in order to preventthe head from swaying during photographing. The head may be restrainedwith a band as necessary for fixing. Moreover, the headgear itself isnot limited to the above configuration. The body of the headgear may beformed by two or more bands.

When the headgear H is mounted, an amount of protrusion of the right andleft bars 84 from the slider 82 is adjusted according to the size of thehead. The longitudinal position of the slider 82 serving as connectingposition adjusting means and the vertical position of the hole areadjusted so as to position the right and left face bow F insertion holes87 on the sides of the central position of the mandibular condyles ofthe patient. In general, the side position of the center of themandibular condyles is disposed about 12 mm forward from the upper edgeof a tragus to an angulus oculi lateralis and about 5 mm lower. Thus,the adjustment is made using this position as a guide.

Then, the face bow F is prepared. As shown in FIGS. 15 and 16, the endsof the right and left legs 70 are inserted respectively into the facebow F insertion holes 87 and make contact with a skin. Further, byadjusting the position of the nose piece 71 and readjusting the positionof the head, the face bow F is adjusted so as to be leveled on apredetermined standard plane. At this point, the adjustment is made withreference to the level 76.

In the present specification, the horizontal plane (standard plane)where the face bow F is positioned may be referred to as a TYA plane.The TYA plane is a horizontal plane including the center of the rightand left mandibular condyles of a patient or a position in the vicinityof the center. The standard plane for mounting the face bow F on thepatient is not limited to the TYA plane. Conventional standard planessuch as the Frankfurt plane (hereinafter, may be referred to as FHplane) and the Camper's plane may be used. Alternatively the face bow Fmay be mounted on a patient by using another plane as a standard plane.With the level 76 and the nose piece 71 whose position can be adjusted,it is possible to perform correct setting on the standard plane.

Subsequently, the X-ray CT device 40 is started while the above state ismaintained, so that three-dimensional image data on thetemporomandibular joint area is obtained.

At this point, the marking members 75 disposed near the mandibularcondyles are also arranged in the temporomandibular joint area and arephotographed together. Therefore, it is possible to calculate aclearance (a distance of closest approach) between the mandibularcondyle and the marking member 75 according to the coordinates of thecontour of the mandibular condyle, the coordinates of a marking, and soon in the three-dimensional image data (see FIG. 18). The presentembodiment comprises an approach distance arithmetic section 52. Whenthe positions of the mandibular condyle and the marking member 75 arespecified by clicking or the like in a tomogram on a display, theapproach distance arithmetic section 52 calculates a distance betweenthe mandibular condyle and the marking member 75 on the basis of thecoordinates of the mandibular condyle and the marking member 75. Somefunctions of an arithmetic section 40D of the X-ray CT device 40 may beused as the approach distance arithmetic section 52.

Further, a distance between the right and left marking members isdetermined indirectly by a distance between the right and left face bowF mounting bodies 86 of the headgear H and directly by measuring adistance between the right and left markings of the face bow F.

Even at the completion of photographing in the X-ray CT device 40, theheadgear H and the face bow F are kept as they are, an impression of theupper jaw is obtained using the bite fork 72, and the three-dimensionalpositional relationship between the temporomandibular joint and amaxillary occlusion plane is obtained.

Further, the three-dimensional image data serving as the arithmeticresult is transmitted to the stereolithography machine 50 andstereolithography is performed on the basis of the three-dimensionalimage data, so that a solid model of the right and left mandibularjoints is constructed.

In this case, the positions corresponding to the marking members 75 arelaterally opposed to each other with respect to the center of themandibular condyles. Thus, it is preferable to set the formation rangeduring stereolithography while positioning the marking members 75 at thecenter of the height direction.

Then, the mandibular condyle model 14 and the maxillary fossa model 22are mounted on the occludator K which are constituted of the solidmodel. Further, the lengths of the right and left bars 10, which areinserted into the insertion holes in the rear of the upper bow-shapedpart 1, are adjusted in such a way that a distance between the verticalparts 8B of the right and left joint mounting parts 8 is equal to thepreviously determined distance between the right and left markingmembers 75.

Subsequently, the screw is turned in the forward/reverse direction toadjust the lateral positions of the articular condyle model 14 and thearticular fossa model 22 in such a way that a distance between theadjacent vertical part 8B (or the marking member 75) and the articularcondyle model 14 and the articular fossa model 22 is equal to thedetermined distance of closest approach.

Further, the spring 30 having a vertical axis is mounted. With thespring 30, it is possible to positively keep a contact between themandibular condyle and the maxillary fossa, thereby reproducing aopening/closing movement and a lateral movement.

In this case, as shown in FIGS. 1 and 19, a positioning hole 90, whichpermits the insertion of the insertion part 74 provided on the end ofthe face bow F, penetrates the right and left vertical part 8B on aposition almost as high as the center of the condyle of the mandibularcondyle model 14. In a state in which the insertion part 74 is insertedinto the positioning hole 90, the marking member 75 is positioned almoston an opening end inside the positioning hole 90. The positioning hole90 constitutes a connecting part on of the occludator.

Then, as shown in FIGS. 20 and 21, the face bow F having been used inphotographing is mounted on the occludator K while being supported bythe right and left positioning holes 90 and the catching part 33. Atthis point, an amount of protrusion of the incisal pin 4 from the upperbow-shaped part 1 is adjusted, so that the face bow F is leveled and ispositioned on the TYA plane on the occludator K.

Subsequently, an upper jaw tooth mold is fixed on the washer of theupper bow-shaped part 1 with gypsum or the like. At this point, theupper jaw tooth mold is mounted on the washer of the upper bow-shapedpart 1 while being positioned on a mark of the bite fork 72 mounted onthe face bow F. Thereafter, a lower jaw tooth model is fixed on thewasher of the lower bow-shaped part 2 so as to interpose a bite havingrecorded upper and lower occlusion.

Thus, the three-dimensional positional relationship between theocclusion plane and the right and left temporomandibular joints 3 in aliving body is reproduced on the occludator K. That is, not only thestructure of the temporomandibular joint of the patient, in which thestructure of the joint 3 is the target, but also a distance between theright and left temporomandibular joints and the occlusion plane arereproduced by simple means on the same positions as three-dimensionalpositions in the living body.

In this way, in the system using the occludator K and the face bow F,the three-dimensional shapes of the right and left temporomandibularjoints are reproduced on the occludator K according to the actual shapesof the temporomandibular joints of the patient. Further, a distancebetween the right and left temporomandibular joints and the occlusionplane are also reproduced on the occludator K with almost the samepositional relationship as the living body.

That is, since a lower jaw movement (opening/closing movement, lateralmovement, etc.) of the target patient can be reproduced in athree-dimensional manner, it is possible to achieve a technique forfabricating a crown prosthesis (crown and bridge), a partial dentalplate, and a full denture most suitably for the patient.

Moreover, since occlusion unique to the patient can be reproduced, it ispossible to obtain diagnoses and treatments of occlusion and developtreatment plans during diagnoses of improper occlusion and prostheseswith higher accuracy.

The present embodiment described the example where the models 14 and 22are mounted by the mounting nuts 15 and 23. The configuration is notlimited to the above. For example, as shown in FIGS. 22A and 22B, an endof the mounting member 13 has a ring-shaped part 92 which has a verticalaxis and permits the insertion of the pedestal 14 b of the solid model.The pedestal 14 b of the solid model is inserted into a concave portionof the ring-shaped part 92, and the end of a screw 93 making a screwingconnection is brought into contact with the ring-shaped part 92.Further, as shown in FIG. 23, the models 14 and 22 may be mounted byscrewing into the pedestal 14 b made of resin.

In this case, the configuration of FIGS. 24A and 24B are alsoapplicable. FIGS. 24A and 24B show examples where the cross section ofthe pedestal 14 b and the concave opening of the ring-shaped part 92 forthe insertion of the pedestal 14 b are both shaped like rectangles.Further, the pedestal 14 b is shaped so as to be engaged into theconcave portion of the ring-shaped part 92, that is, the pedestal 14 band the ring-shaped part 92 are similar in shape. The cross section andthe opening are shaped like polygons such as a rectangle, so thatpositioning can be readily performed in a circumferential direction aswell as the horizontal direction. Moreover, since the pedestal 14 b isslightly elastic, the pedestal 14 b may be fit into the concave portionof the ring-shaped part 92 while being tightened slightly. In this case,a fastening device such as the screw 93 is not always necessary.

In the present embodiment, the three-dimensional image data calculatedby the X-ray CT device 40 is used as it is. The processing is notlimited to the above.

For example, data correcting means may be provided for the followingprocessing:

Regarding mandibular condyles, standard mandibular condyle model dataserving as standard or ideal data is registered in a database for eachpredetermined category on the basis of three-dimensional image data orthe like about a number of temporomandibular joints. First, on aspecific cross-sectional image such as a longitudinal section imagepassing through the center of the condyle in front view, standardmandibular condyle model data on the database is selected on the basisof a predetermined classification criterion on the shapes of contoursother than the protruding portion of the top. The model data is close tothe three-dimensional image data having been calculated by the X-ray CTdevice 40. Subsequently, as shown in FIG. 39, a comparison is madebetween a ratio of a distance H1 to the top to a width W1 (calculatedand stored beforehand) on a predetermined standard plane SP (e.g., ahorizontal plane at the center of the condyle) of the mandibular condyleregarding the selected standard mandibular condyle model data (brokenline), and a ratio of a distance H2 to the top to a width W2 on thepredetermined standard plane for the three-dimensional image data (W1=W2in FIGS. 24A and 24B and a difference may occur). When (H2/W2) is notlarger than a predetermined value of (H1/W1), e.g., 0.6, it is decidedthat the protrusion of the top of the mandibular condyle wears out morethan necessary in the three-dimensional data, and the three-dimensionalimage data is corrected such that the top of the mandibular condyle ofthe three-dimensional image data having been calculated by the X-ray CTdevice 40 is shaped like or close to the top of the standard model. InFIG. 39, a chain line shows an example of protrusion after correction.The protrusion is corrected to, e.g., 0.7 of the protrusion of thestandard mandibular condyle. An amount of correction such as 0.7 may beinputted on the spot or automatically calculated on the basis of theratios (H2/W2) and (H1/W1).

With this data correcting means, a condyle model close to a healthycondition is reproduced instead of a worn and distorted condyle, so thatocclusion closer to a healthy condition than the present state isreproduced. Accordingly, prostheses can be fabricated and occlusion istreated.

Further, the following configuration is also applicable: two or morekinds (e.g., 256 kinds) of standard mandibular condyle model data andstandard maxillary fossa model data are stored in the database accordingto the predetermined classification, selecting means is provided whichselects standard mandibular condyle model data and standard maxillaryfossa model data in the database that are close to the three-dimensionalimage data having been calculated by the X-ray CT device 40,stereolithography is performed using the standard mandibular condylemodel data and standard maxillary fossa model data selected by theselecting means, and the mandibular condyle model 14 and the maxillaryfossa model used in the occludator K are constructed.

In this case, it is possible to reduce the accuracy of three-dimensionaldata calculated by the X-ray CT device 40.

When the stereolithography machine 50 is disposed away from the X-ray CTdevice 40, three-dimensional image data calculated by the X-ray CTdevice 40 has to be transmitted through a communication device such asthe Internet in the present embodiment, resulting a large amount oftransmission data. In this processing method, both of the X-ray CTdevice 40 and the stereolithography machine 50 are provided with thedatabases, so that only identification information about the number orthe like of the standard model has to be transmitted through thecommunication device. Thus, it is possible to considerably reduce anamount of data to be transmitted.

Moreover, the following configuration is also applicable: models areprepared according to the standard mandibular condyle model data andstandard maxillary fossa model data in the database (the model does nothave to be made of resin), selecting means is provided which selectsstandard mandibular condyle model data and standard maxillary fossamodel data in the database that are close to the three-dimensional datahaving been calculated by the X-ray CT device 40, and a model selectedby the selecting means is extracted from prepared models and is mountedand used on the occludator K.

In this case, the stereolithography machine 50 is unnecessary.

In a classification example of standard model data registered in thedatabase, for example, classification and registration are performed byfour parameters of a frontal shape, a side shape, a top shape, and asize of a cross-sectional image passing through the center of thecondyle, and data close to the three-dimensional data calculated by theX-ray CT device 40 is automatically selected according to theclassification. As a matter of course, classification is not limited tothe above. Characteristics of the contours of other maxillary fossas andmandibular condyles may be extracted and classification may be performedon the basis of the characteristics. Various kinds of matchingtechniques can be used to decide whether data is close or not. Simply, amodel to be used may be selected from two-dimensional X-ray radiographs.

Further, in this embodiment, data is transmitted from the X-ray CTdevice 40 to the stereolithography machine 50 through a communicationdevice such as an Internet device. The following transmission is alsoapplicable: the three-dimensional image data calculated by the X-ray CTdevice 40 is divided into a plurality of two dimensional image dataalong the Z axis for stereolithography in the X-ray CT device 40, andthen the plurality of two-dimensional image data is transmitted to thestereolithography machine 50. In this case, even two-dimensional dataresults in a large amount of transmission data. Thus, groups of two ormore coordinates for specifying each corresponding contour of thetwo-dimensional image data may be transmitted instead of thetwo-dimensional image data. This processing can considerably reduce anamount of transmission data.

In this embodiment, both of the mandibular condyle model 14 and themaxillary fossa model 22 correspond to the outer contours of thetemporomandibular joints of a target patient. Models are not limited tothe above. For example, one of the models 14 and 22 may be ageneral-purpose model (identical only in size to the other).

In this embodiment, the coil spring was described as an example of anelastic body. A material such as rubber is also applicable and theinstallation position is not limited to the above. In short, at leastthe mandibular condyle model 14 and the maxillary fossa model 22 have tobe vertically brought into contact with each other via the elastic body.An urging state close to a standard or ideal urging state of muscle in aliving body may be reproduced on the occludator by arranging theposition of the elastic body.

Further, by using the solid model prepared by stereolithography, anartificial joint for a temporomandibular joint may be formed by abiocompatible material, e.g., titanium and ceramics. For a person whohas broken a joint or extracted a joint due to a disease, a joint uniqueto the person can be restored or the most suitable shape for a maxillaryfossa can be provided.

A supplementary explanation will be given on stereolithography based onthe three-dimensional image data having been photographed and calculatedby the X-ray CT device 40.

Although forming may be performed over the photographing area of theX-ray CT device 40 as a forming area of stereolithography, thephotographing area may be displaced, that is, may be varied according tothe technique of the photographer as shown in FIGS. 40 to 43, so thatthe position of a joint may be different for each product. Moreover,three-dimensional data has to be calculated uselessly. In FIGS. 40 to43, reference character A denotes an image pickup area, referencecharacter B denotes the forming area, and reference character C denotesan imaged target or imaging center.

For this problem, in the present embodiment, the marking member opposedto the center of the mandibular condyle from the side is photographedtogether with a joint part, so that the forming area B can be positionedas follows:

First, as described above, the position corresponding to the markingmember 75 is laterally opposed to the center of the mandibular condyle.Thus, the forming area B during stereolithography is set while themarking member 75 is positioned at the center of the height direction.Hence, as shown in FIGS. 40 and 41, the center of the upper and lowersolid models can be set at the center of the forming area B. As aresult, when the solid model is mounted on the occludator, the center ofthe mandibular condyle of the solid model can be aligned with a positionlaterally opposed to the marking member of the face bow F connected tothe occludator.

Further, the size of the forming area B is determined according to theposition of the marking member, thereby minimizing the forming area B.For example, when the position of the marking member is set so as tomake contact with a skin of a patient, the center of the mandibularcondyle is generally positioned about 20 mm inside the marking member.Therefore, in this case, as shown in FIG. 44, a cylinder around avertical axis P serves as the forming area B. The vertical axis P ispositioned 20 mm inside along the lateral direction from the markingmember. The cylinder is 15 mm in radius and is higher or smaller thanthe marking member by 15 mm, that is, 30 mm in height. The shapedpedestal is added vertically to the cylinder. Numbers on the imagepickup area A of FIG. 44 are just examples and are varied with the sizeof a standard temporomandibular joint.

Reference character A in FIG. 44 denotes an ideal photographing area. Onthe assumption that the photographing area A is cylindrical, thephotographing area and the forming area B should be concentric circlesin plan view (view from the top). However, as shown in FIGS. 42 and 43,the center of the photographing area and the area center of the imagedtarget C (a part passing through the center of the mandibular condyle)are readily displaced from each other as described above. In contrast,as described above, the center of the forming area B is specified and isused as a standardized area relative to the marking member, so that evenwhen the photographing area is displaced, forming can be performed whilethe center of the forming area B is aligned with the area center of theimaged target C.

Moreover, the three-dimensional image data photographed and calculatedby the X-ray CT device 40 includes noise, such as floating noise, uniqueto a living body and other kinds of noise. Thus, when thethree-dimensional data is used for forming as it is, a formedthree-dimensional object has less accurate contours.

For this reason, this embodiment presents a processing method as anexample of noise processing, in which expansion is temporarily performedinto a plurality of two-dimensional images in a multidirectional manner,noise is reduced and the contour of an object is extracted for each ofthe two-dimensional images, and then the images are rearranged in athree-dimensional manner.

Further, the maxillary fossa is disposed so closely as to cover themandibular condyle from above and thus the mandibular condyle model andthe maxillary fossa model may not be separated well. Hence, instead ofor in parallel with the first noise processing, it is preferable toperform second and third noise processing (described below) on thethree-dimensional data.

The second noise processing is a processing method of labeling thevertical consecutiveness of pixels in the image pickup area A of thethree-dimensional data and removing inconsecutive pixels as floatingnoise. For example, pixels on the underside of an image area are labeledand labeling is performed between the labeled pixels and an array, whichis one stage above the pixels, so that a continuous area (surface) isspecified. This processing is performed to the top face of the imagearea, and the pixel value of an unlabeled pixel is set at 0 and removed.This processing is also performed from the top face to the underside ofthe image area. Hence, even from an object shaped like a letter “J,”floating noise components can be removed.

In the third noise processing, noise components are removed by properlychanging, for each pixel, a parameter for correcting a concentration, sothat a boundary of a temporomandibular joint is sharpened. That is, athreshold value Th (e.g., Th=α×A:0<α<1) is determined by an averagepixel value A of the obtained three-dimensional data, an average A1 ofthe number of pixels around a target pixel is determined for each targetpixel, and a concentration of the target pixel is corrected according toa difference between A1 and the threshold value Th. For example, asshown in FIGS. 45A and 45B, (A=Th), a brightness relatively decreases ina pixel where brighter than the threshold value and a brightnessrelatively increases in a pixel where darker than the threshold value.That is, a concentration of each pixel is corrected according toinformation about the vicinity of the target pixel relative toinformation about the overall image. Thus, in a part where a colorcontinuously changes, a somewhat faint color appears and noise isreduced. Conversely, in a part where a contrast rapidly changes, thatis, on a boundary of the joints, colors are sharpened. It was confirmedthat this processing removes noise components and a boundary oftemporomandibular joints is sharpened.

Embodiment 2 will be described below in accordance with the accompanyingdrawings. The same components as the above-described embodiment will beindicated by the same reference numerals and characters.

The basic configuration of Embodiment 2 is similar to that ofEmbodiment 1. A face bow F and a part of an occludator that correspondsto the face bow F are different from those of Embodiment 1.

First, the configuration of the face bow F of the present embodimentwill be discussed below.

As shown in FIGS. 25 to 27, in the body of the face bow F, legs 100 onthe right and left are symmetrically opposed to each other. Each of thelegs 100 is shaped like a letter L in plan view. The leg 100 isconstituted of a leg body 101 which stretches to the front and rear anda platy horizontal part 102 which is connected to the base of the legbody 101 and stretches to the other opposed leg 100.

As shown in FIG. 26, the right and left horizontal parts 102 arevertically overlaid on the other so as to slide in the lateraldirection. The upper horizontal part 102 has a long opening 104stretching in the lateral direction, and the lower horizontal part 102has a tapped hole which can be screwed to the axis of a fastening screw103 penetrating the long hole 104. The fastening screw 103 is loosened,an amount of overlapping of the right and left horizontal parts 102 (adistance between the right and left leg bodies 101) is adjusted, andthen the fastening screw 103 is tightened again for fixing.

Reference numeral 105 denotes two protrusions which protrude from thelower horizontal part 102 into the long opening 104. When the horizontalparts 102 are slid by loosening the fastening screw 103, the protrusionsregulate the two horizontal parts 102 so as to have a slide only in thelateral direction. Moreover, the regulating mechanism permitting onlylateral sliding is not limited to the above. A known linear guidemechanism and so on are also applicable.

As described above, although the right and left horizontal parts 102 arepartially overlaid on the other in the vertical direction, the right andleft leg bodies 101 are positioned on the same plane by a step.

Ear rods 106 to be inserted into the external auditory meatuses of apatient are provided on the ends of the right and left leg bodies 101. Aplaty or stick-like protrusion 107 is provided which protrudes from amidpoint of the ear rod 106 to the front. A marking member 75 isprovided on the protrusion 107. The marking member 75 is set on aposition presumed to be laterally opposed to the center of a mandibularcondyle. For example, when the standard plane of the face bow F is theFH plane, the marking member 75 is preferably positioned about 12 mmforward from the center of the ear rod 106. Also when other standardplanes are used, according to the standard plane used by the face bow F,the position of the marking member 75 relative to the ear rod 106 is seton a position presumed to be opposed to the center of the mandibularcondyle. The marking member 75 is made of a material not permitting thepassage of X-ray beams, e.g., a stainless or aluminum ball.

The position of the marking member 75 may be slid to the front and rear.In this case, it is preferable to accordingly slide the position of anear rod hole 120 of the occludator to the front and rear.

In this case, as shown in FIG. 28, the protrusion 107 for supporting themarking member 75 may laterally protrude from the leg body 101. FIG. 28illustrates an example where the protrusion 107 is supported so as toslide in the lateral direction with respect to the leg body 101.

Further, a horizontal bar 108 is disposed across the right and left legbodies 101 in parallel with the horizontal parts 102. The horizontal bar108 is connected so as to move laterally relative to the leg bodies 101.In the present embodiment, long openings 108 b stretching in the lateraldirection are formed in the horizontal bar 108 so as to face the legbodies 101. The shaft of a screw 109 penetrating the long opening 108 bis screwed into a tapped hole formed in the leg body 101.

A bite fork 72 and a nose piece (not shown in FIG. 25) are mounted onthe horizontal bar 108. Reference numeral 108 a denotes the mountingportion of the nose piece.

Further, a level 76 is mounted on each of the leg bodies 101.

The following will describe the mounting of the nose piece onto thehorizontal bar 108. As shown in FIGS. 29 and 30, there are provided: acolumn 111 which has a fit portion 111 a and stretches upward, the fitportion 111 a being fit and mounted onto the horizontal bar 108 from thefront or rear, a screw rod 112 which has a vertical shaft whose upperand lower ends are supported by the column so as to freely rotate, and aslider 113 composed of a nut member which is screwed to the screw rod112 and is vertically displaced by the rotation of the screw rod 112.The slider 113 is guided by the column 111 so as to move only in thevertical direction.

A cylindrical member 114 which has a longitudinal axis and a throughhole is supported by the slider 113. A nose piece body 116 is providedon an end of a rod 115 which vertically penetrates the cylindricalmember 114. This mechanism constitutes a position adjusting mechanism.

Reference numeral 117 denotes a screw for fixing onto the horizontal bar108 of the column, reference numeral 118 denotes a screw which isscrewed into the slider 113, brings an end of the shaft into contactwith the screw rod 112, and fixes the position of the slider 113, andreference numeral 119 denotes a screw which brings an end of the shaftin contact with the rod 115 and fixes the rod 115 to the cylindricalmember 114.

Further, the level 76 is mounted on each of the leg bodies 101.

The legs 100 and the protrusions 107 are made of a radiolucent materialand a material of a predetermined strength, e.g., duralumin, an acrylicsheet, a baking plate, fiber reinforced plastics, and so on. Atransparent material is more preferable.

Although the basic configuration of the occludator is similar to that ofEmbodiment 1, the ear rod holes 120 for inserting the ear rods 106 ofthe face bow F are provided instead of the positioning holes 90 enablingthe insertion of the insertion parts 74. The ear rod holes 120constitute a connecting part of the occludator. As shown in FIG. 25, theear rod hole 120 is formed 12 mm backward from a position correspondingto the center of the mandibular condyle, that is, a position where thepositioning hole is formed. As a result, when the ear rods 106 areinserted into the ear rod holes 120, the position of the marking member75 is laterally opposed to the position corresponding to the center ofthe mandibular condyle.

Then, as shown in FIG. 31, the right and left ear rods 106 of the facebow F are inserted into the right and left external auditory meatuses ofa patient until the protrusions 107 make contact with a skin, and adistance between the right and left leg bodies 101 is adjusted, and thenthe fastening screw is tightened to combine the right and left legs 100.Thereafter, the nose piece member is mounted on the horizontal bar 108,the nose piece member and the head position of the patient are adjustedso as to level the upper face of the face bow F on the FH plane, andthen the screws are tightened for fixing. At this point, the degree oflevelness of the face bow F is confirmed by the right and left levels76.

Subsequently, photographing is performed by an X-ray CT device 40 in theabove-described manner and a solid model is constructed bystereolithography. The face bow F is kept as photographed.

Then, the solid model is mounted on the occludator in the same manner asEmbodiment 1.

Subsequently, as shown in FIG. 32, the ear rods 106 of the kept face bowF are inserted into the ear rod holes 120 of the occludator to connectthe face bow F to the occludator. The nose piece is detached beforehand.

While the degree of levelness is confirmed by the levels 76 of the facebow F, a length of an incisal pin is adjusted to level the face bow F.

Then, an upper jaw tooth mold whose impression has been obtained ismounted on an upper bow-shaped part. Further, a material is interposedwhere occlusion has been obtained to form upper and lower prostheses,and a lower jaw tooth mold is mounted while occluding to the upper jawtooth mold.

In the case of the face bow F of the present embodiment, a headgear isunnecessary during photographing. Further, the face bow F can be morereadily set on the standard plane with high accuracy and an occlusionplane and so on can be positively copied to the occludator.

In the present embodiment, the position of the nose piece relative tothe face bow F is adjusted, so that the face bow F can be positioned andadjusted more positively on three points of the head of the patient.Thus, it is possible to align the face bow F with the standard plane (FHplane in the present embodiment) with higher accuracy. Moreover, thedegree of levelness can be confirmed more positively by the levels 76.

The standard plane is not limited to the FH plane. Other planes can actas the standard plane without any problems.

Other configurations and operations/working effects are similar to thoseof Embodiment 1.

Embodiment 3 will be described below in accordance with the accompanyingdrawings. The same members as the above-described embodiments will beindicated by the same reference numerals and characters.

The basic configuration of Embodiment 3 is similar to that of Embodiment2. A face bow F is different from that of Embodiment 2.

Referring to FIGS. 33 to 35, the face bow F of the present embodimentwill be discussed below.

As with Embodiment 2, right and left legs 100 of the present embodimentare shaped like letters L in plan view, and right and left horizontalparts 102 are vertically overlaid on the other. However, in the presentembodiment, a long opening stretching in a lateral direction is formedin each of the horizontal parts 102. The horizontal parts 102 are guidedby a box 122 so as to move only in the lateral direction. The top plateand the bottom plate of the box 122 have tapped holes in positionsvertically opposed to the long openings formed in the horizontal parts102. A fastening screw 103 penetrates the upper and lower tapped holesand the long openings of the horizontal parts 102 from above and isscrewed into a nut member 126 below. A washer 123 is interposed betweenthe top plate of the box and the upper horizontal part 102, between theupper and lower horizontal parts 102, and between the lower horizontalpart 102 and the bottom plate of the box. Then, in a state in which thefastening screw 103 is loosened, the right and left legs 100 aresymmetrically displaced and positioned, and then the fastening screw 103is tightened again. Thus, a distance between the right and left legbodies 101 is adjusted.

The nut member 126 has a vertical axis. An upper tapped hole forscrewing the fastening screw is formed in the upper side of the nutmember 126, and a lower tapped hole for mounting a center positioningpin 127 is formed in the bottom of the nut member 126. The centerpositioning pin 127 is a rod having a vertical axis. The top of thecenter positioning pin 127 has a male screw screwed into the lowertapped hole.

Further, in the present embodiment, a horizontal bar 108 for mounting abite fork and a nose piece is fixed on the box 122. The right and leftends of the horizontal bar 108 penetrate the leg bodies 101,respectively. Thus, the right and left leg bodies 101 can slidelaterally with respect to the horizontal bar 108. Reference numeral 108a denotes the mounting portion of the nose piece.

Moreover, in the present embodiment, marking members 121 are providedalso on the ends of ear rods 106. Besides, a level 76 is mounted on thehorizontal bar 108.

In the face bow F of the present embodiment, the right and left ear rods106 are inserted and mounted into the right and left external auditorymeatuses of a patient, the face bow F is set so as to be positioned on astandard plane such as the FH plane, and an impression is obtained.

At this point, in the present embodiment, the center positioning pin 127enables an inclination of a face to be recognized visually, therebyreadily adjusting an inclination of a face and so on. When the face bowF is mounted on the occludator, the center positioning pin 127 isunnecessary and thus removed. The center positioning pin 127 may be usedinstead of an incisal pin.

FIG. 36 shows that the face bow F is connected to the occludator.

In the present embodiment, two marking members 75 are disposed on theright and left so as to be arranged in the longitudinal direction. Thisis because the longitudinal direction (X-axis direction) is readilyrecognized.

Other configurations and operations/working effects are similar to thoseof the above-described embodiments.

In all the embodiments, the face bow F has the marking members 75 inorder to obtain a reference for generating a solid model withstereolithography. Thus, even when the marking members 75 are notprovided, a setting is correctly made on a standard plane (FH plane andso on) by the face bow F and an occlusion plane obtained by the correctstandard plane can be copied to the occludator. Therefore, the face bowwhich can make a setting on the standard plane more positively andsample the occlusion plane is connected to the occludator of the presentinvention which can reproduce an articular movement closer to atemporomandibular joint of a patient, so that more prostheses or thelike can be provided under occlusion conditions of the patient.

Moreover, the body of the face bow F is made of a radiolucent materialin order to prevent the face bow F from causing problems duringphotographing. When no problem occurs, the face bow F does not have tobe made of a radiolucent material.

Further, an elastic sheet having a thickness corresponding to a gapbetween the mandibular condyle and the maxillary fossa of theembodiments may be interposed between the mandibular condyle model andthe maxillary fossa model which are mounted on the occludator. Further,a lubricant or the like may be applied to a contact surface between themandibular condyle model and the maxillary fossa model to adjustsliding.

As shown in FIGS. 37 and 38, the following configuration is alsoapplicable: a distance between the right and left legs is adjusted by agear mechanism, and the right and left leg bodies 101 are equal indisplacement in the lateral direction. Reference numeral 201 denotes afixing screw. That is, the mechanism for adjusting a distance betweenthe right and left legs is not limited to those of the embodiments.Moreover, the mechanism for positioning the nose piece is not limited tothe above.

INDUSTRIAL APPLICABILITY

As described above, with the present invention, it is possible tofabricate a crown prosthesis and so on more suitably for a target personand achieve a more appropriate diagnosis, treatment and so on ofocclusion.

1. An occludator, comprising a lower bow-shaped part for mounting alower jaw tooth mold, an upper bow-shaped part for mounting an upper jawtooth mold, and right and left joints which connect the lower bow-shapedpart and the upper bow-shaped part and enable a movement including anopening/closing movement and a lateral movement, characterized in thatthe joint comprises an artificial condyle which is detachably mounted onthe lower bow-shaped part and protrudes upward and an artificialarticular fossa which is detachably mounted on the upper bow-shaped partand is opposed to the artificial condyle from above, the artificialcondyle and the artificial articular fossa are both identical in contourto the mandibular condyle or the maxillary fossa of a person whoseimpression has been obtained during fabrication of the upper jaw toothmodel.
 2. The occludator according to claim 1, characterized in that theoccludator comprises an elastic body for applying an urging force in adirection of bringing the lower bow-shaped part and the upper bow-shapedpart relatively close to each other.
 3. The occludator according toclaim 1, characterized in that the joint is constituted of an upperjoint and a lower joint which are opposed to each other, the upper jointis constituted of an upper mounting member supported by the upperbow-shaped part, a maxillary fossa model, and first mounting means fordetachably mounting the pedestal of the maxillary fossa model on theupper mounting member, and the lower joint is constituted of a lowermounting member fixed on the lower bow-shaped part, a mandibular condylemodel, and second mounting means for detachably mounting a pedestal ofthe mandibular condyle model on the lower mounting member.
 4. Theoccludator according to claim 3, characterized in that the firstmounting means is constituted of a male screw part formed on the uppermounting member, a cylindrical member having a female screw formed in aninner surface, the female screw enabling to be screwed to the malescrew, and an inner flange which is formed integrally with thecylindrical member, forms a hole permitting passage of the maxillaryfossa model, and can make contact with a periphery of the pedestal ofthe maxillary fossa model, and the periphery of the pedestal of themaxillary fossa model is sandwiched between the upper mounting memberand the inner flange by screwing the female screw to the male screw. 5.The occludator according to claim 3 4, characterized in that the secondmounting means is constituted of a male screw part formed on the lowermounting member, a cylindrical member having a female screw formed in aninner surface, the female screw enabling to be screwed to the malescrew, and an inner flange which is formed integrally with thecylindrical member, forms a hole permitting passage of the mandibularcondyle model, and can make contact with a periphery of the pedestal ofthe mandibular condyle model, and the periphery of the pedestal of themandibular condyle model is sandwiched between the lower mounting memberand the inner flange by screwing the female screw to the male screw. 6.The occludator according to claim 3, characterized in that the firstmounting means comprises a ring-shaped part which is formed on an end ofthe upper mounting member and has an inner concave part permittinginsertion of the pedestal of the maxillary fossa model, and a fixingscrew which laterally penetrates the ring-shaped part while beingconnected to the ring-shaped part by screwing, and has an end screwedinside the pedestral from a part where the female screw is not formed onthe side of the pedestal of the maxillary fossa model.
 7. The occludatoraccording to claim 6, characterized in that the pedestal in crosssection and the concave part of the ring-shaped part are both polygonal,and the pedestal is so shaped as to be engaged with the concave part ofthe ring-shaped part.
 8. The occludator according to claim 3 4,characterized in that the second mounting means comprises a ring-shapedpart which is formed on an end of the lower mounting member and has aninner concave part permitting insertion of the pedestal of themandibular condyle model, and a fixing screw which laterally penetratesthe ring-shaped part while being connected to the ring-shaped part byscrewing, and has an end screwed inside the pedestal from a part wherethe female screw is not formed on a side of the mandibular condylemodel.
 9. The occludator according to claim 8, characterized in that thepedestal in cross section and the concave part of the ring-shaped partare both polygonal, and the pedestal is so shaped as to be engaged withthe concave part of the ring-shaped part.
 10. The occludator accordingto claim 3, characterized by further comprising upper positioning meansfor regulating a position of the pedestal of the maxillary fossa modelrelative to the upper mounting part.
 11. The occludator according toclaim 3, characterized by further comprising lower positioning means forregulating a position of the pedestal of the mandibular condyle modelrelative to the lower mounting part.
 12. The occludator according toclaim 1, characterized by further comprising position adjusting meansfor laterally adjusting a position of at least one of the artificialcondyle and the artificial articular fossa.
 13. The occludator accordingto claim 1, characterized in that two or more pairs of the mandibularcondyle model and the maxillary fossa model are provided, and a pair ofthe mandibular condyle model and the maxillary fossa model is used asthe artificial condyle and the artificial articular fossa according to ashape of the temporomandibular joint of a person whose impression hasbeen obtain during fabrication of the upper jaw tooth model.
 14. Theoccludator according to claim 1, characterized by further comprisingconnecting parts on a pair of lateral positions in the occludator, theconnecting parts connecting the face bow.
 15. A face bow used for theoccludator according to claim 14, the face bow reproducing a positionalrelationship between a temporomandibular joint and an occlusion plane onthe occludator, characterized in that the face bow comprises a face bowbody having a pair of right and left legs stretching symmetrically, aconnecting part which is provided on an end of the leg and can beconnected to the connecting part of the occludator, and a nose piecewhich is supported by the face bow body and brought into contact with ahollow on an upper part of a nose of a patient, the nose piece comprisesa position adjusting mechanism capable of adjusting a position at leastin a vertical direction and a longitudinal direction with respect to theface bow body, the connecting part provided on the end of the leg is anear rod which can be inserted into an external auditory meatus of apatient the connecting part of the occludator is constituted of aninsertion hole permitting insertion of the ear rod, the face bow body ismade of a material permitting passage of an X-ray beam, and the face bowbody comprises a marking member which is laterally opposed to a centerof a mandibular condyle of a patient or a vicinity of the center infront of the ear rod and is made of a material not permitting passage ofan X-ray beam, and a supporting member causing the leg to support themarking member.
 16. The face bow according to claim 15, characterized inthat the face bow body comprises a level.
 17. A face bow for reproducinga positional relationship between a temporomandibular joint and anocclusion plane on the occludator, characterized in that the face bowcomprises a face bow body having a pair of right and left legsstretching symmetrically, an ear rod which is provided on an end of theleg and can be inserted into an external auditory meatus of a patient,and a nose piece which is supported by the face bow body and broughtinto contact with a hollow on an upper part of a nose of a patient, theface bow further comprises a regulating mechanism for sliding the pairof right and left legs only in a lateral direction.
 18. The face bowaccording to claim 17, characterized in that the face bow body is madeof a material permitting passage of an X-ray beam, and the face bow bodycomprises a marking member which is laterally opposed to a center of amandibular condyle of a patient or a vicinity of the center in front ofthe ear rod and is made of a material not permitting the passage of anX-ray beam, and a supporting member causing the leg to support themarking member.
 19. An occlusion confirming system, characterized inthat the system comprises a CT device for photographing atemporomandibular joint of a target person, a stereolithography machinefor forming a solid model of the temporomandibular joint on a basis ofthree-dimensional image data of the temporomandibular joint specified byimage information photographed by the CT device, and an occludatorincluding a lower bow-shaped part for mounting a lower jaw tooth mold,an upper bow-shaped part for mounting an upper jaw tooth mold, and rightand left joints for connecting the lower bow-shaped part and the upperbow-shaped part, the joint comprises an artificial condyle which ismounted on the lower bow-shaped part and protrudes upward and anartificial articular fossa which is mounted on the upper bow-shaped partand is opposed to the artificial condyle from above, the artificialcondyle and the artificial articular fossa are each constituted of thesolid model formed by the stereolithography machine, and the solidmodels of the artificial condyle and the artificial articular fossa areintegrally formed in a separable manner.
 20. (canceled)
 21. (canceled)22. The occlusion confirming system according to claim 19, characterizedby further comprising an elastic body for applying an urging force in adirection of bringing the lower bow-shaped part and the upper bow-shapedpart relatively close to each other.
 23. The occlusion confirming systemaccording to 19, characterized in that the joint is constituted of anupper joint and a lower joint which are opposed to each other, the upperjoint is constituted of an upper mounting member supported by the upperbow-shaped part, a maxillary fossa model, and first mounting means fordetachably mounting a pedestal of the maxillary fossa model on the uppermounting member, and the lower joint is constituted of a lower mountingmember fixed on the lower bow-shaped part, a mandibular condyle model,and second mounting means for detachably mounting a pedestal of themandibular condyle model on the lower mounting member.
 24. The occlusionconfirming system according to claim 23, characterized in that the firstmounting means is constituted of a male screw part formed on the uppermounting member, a cylindrical member having a female screw formed in aninner surface, the female screw capable of being screwed to the malescrew, and an inner flange which is formed integrally with thecylindrical member, forms a hole permitting passage of the maxillaryfossa model, and can make contact with a periphery of the pedestal ofthe maxillary fossa model, and the periphery of the pedestal of themaxillary fossa model is sandwiched between the upper mounting memberand the inner flange by screwing the female screw to the male screw. 25.The occlusion confirming system according to claim 23, characterized inthat the second mounting means is constituted of a male screw partformed on the lower mounting member, a cylindrical member having afemale screw formed in an inner surface, the female screw enabling to bescrewed to the male screw, and an inner flange which is formedintegrally with the cylindrical member, forms a hole permitting passageof the mandibular condyle model, and can make contact with the peripheryof a pedestal of the mandibular condyle model, and the periphery of thepedestal of the mandibular condyle model is sandwiched between the lowermounting member and the inner flange by screwing the female screw to themale screw.
 26. The occlusion confirming system according to claim 5,characterized in that the first mounting means comprises a ring-shapedpart which is formed on an end of the upper mounting member and has aninner concave part permitting insertion of the pedestal of the maxillaryfossa model, and a fixing screw which can laterally penetrate thering-shaped part while being connected to the ring-shaped part byscrewing, and has an end capable of being screwed inward or in contactwith a side of the pedestal of the maxillary fossa model.
 27. Theocclusion confirming system according to claim 23, characterized in thatthe second mounting means comprises a ring-shaped part which is formedon an end of the lower mounting member and has an inner concave partpermitting insertion of the pedestal of the mandibular condyle model,and a fixing screw which can laterally penetrate the ring-shaped partwhile being connected to the ring-shaped part by screwing, and has anend capable of being screwed inward or in contact with a side of thepedestal of the mandibular condyle model.
 28. The occlusion confirmingsystem according to claims 23, characterized by further comprising upperpositioning means for regulating a position of the pedestal of themaxillary fossa model relative to the upper mounting part.
 29. Theocclusion confirming system according to claim 23, characterized byfurther comprising lower positioning means for regulating a position ofthe pedestal of the mandibular condyle model relative to the lowermounting part.
 30. The occlusion confirming system according to claim19, characterized by further comprising position adjusting means forlaterally adjusting a position of at least one of the artificial condyleand the artificial articular fossa.
 31. The occlusion confirming systemaccording to claim 19, characterized by further comprising a face bowincluding a face bow body which is used for reproducing a positionalrelationship between the temporomandibular joint and an occlusion planeon the occludator and has a pair of right and left legs stretchingsymmetrically, characterized in that at least the right and left legsare made of a material permitting passage of a light beam used in the CTdevice, and at least one marking member is provided on an end of each ofthe right and left legs, the marking member being made of a material notpermitting the passage of the light beam.
 32. The occlusion confirmingsystem according to claim 31, characterized in that the face bowcomprises a nose piece which is supported by the face bow body andbrought into contact with a hollow in an upper part of a nose of apatient, and the nose piece comprises a position adjusting mechanismcapable of adjusting a position at least in a vertical direction and alongitudinal direction with respect to the face bow body.
 33. Theocclusion confirming system according to claim 31, characterized in thatthe face bow body comprises a level.
 34. The occlusion confirming systemaccording to claim 31, characterized in that the marking member isdisposed on a position presumed to be laterally opposed to a center ofthe mandibular condyle of a patient.
 35. The occlusion confirming systemaccording to claim 31, characterized by further comprising an ear rod onan end of the leg in the face bow, the ear rod being inserted into anexternal auditory meatus of a patient, and each of right and left sidesof the occludator has an insertion hole for insertion of the ear rod.36. The occlusion confirming system according to 31, comprising aheadgear fixed on a head of a target person, characterized in that thehead gear comprises right and left connecting parts for temporarilyconnecting right and left ends of the face bow and connection positionadjusting means for adjusting a position of the connecting part to apredetermined position.
 37. The occlusion confirming system according toclaim 36, characterized in that the headgear comprises fixing means fortemporarily fixing the headgear to the CT device.
 38. An occlusionconfirming system characterized in that the system comprises a CT devicefor photographing a temporomandibular joint of a target person, astereolithography machine for forming a solid model of thetemporomandibular joint on a basis of three-dimensional image data ofthe temporomandibular joint specified by image information photographedby the CT device, and an occulator including a lower bow-shaped part formounting a lower jaw tooth mold, an upper bow-shaped part for mountingan upper jaw tooth mold, and right and left joints for connecting thelower bow-shaped part and the upper bow-shaped part, the joint comprisesan artificial condyle which is mounted on the lower bow-shaped part andprotrudes upward and an artificial articular fossa which is mounted onthe upper bow-shaped part and is opposed to the artificicial condylefrom above, and at least one of the artificial condyle and theartificial articular fossa is constituted of the solid model formed bythe stereolithography machine, and a database for storing ideal modelinformation about a temporomandibular joint condyle, characterized inthat the system further comprises data correcting means for correctingthree-dimensional data on the temporomandibular joint condyle specifiedby image information photographed by the CT device such that a contourof the temporomandibular joint condyle specified by the imageinformation photographed by the CT device is identical to a contourprotruding closer to an ideal model, when a comparison is made betweenthe coutour of the temporomandibular joint condyle specified by theimage information photographed by the CT device and the correspondingideal model on the database and it is decided that the temporomandibularjoint condyle wears more than a predetermined degree.
 39. (canceled) 40.A temporomandibular joint reproducing system characterized in that thesystem comprises a CT device for photographing a temporomandibular jointof a target person, a stereolithography machine for forming a solidmodel of the temporomandibular joint on a basis of three-dimensionaldata of the temporomandibular joint specified by image informationphotographed by the CT device, and a face bow including a face bow bodywhich is used for reproducing a positional relationship between thetemporomandibular joint and an occlusion plane on the occludator and hasa pair of right and left legs stretching symmetrically, at least theright and left legs are made of a material permitting passage of a lightbeam used in the CT device, a marking member is provided on an end ofeach of the right and left legs on a position presumed to be laterallyopposed to a center of the mandibular condyle of a patient, the markingmember being made of a material not permitting passage of the lightbeam, and a forming area for stereolithography is specified according toa position of the photographed marking member.
 41. (canceled) 42.(canceled)